'4./ 


U.  S.  DEPARTMENT  OF  AGRICULTURE. 

DIVISION  OF  ENTOMOLOGY— BULLETIN  NO    4,. 

L.    O.    HOWARD,    Entomologist. 


THE  CODLING  MOTH 


PREPARED  UNDER  THE  DIRECTION  OF  THE  ENTOMOLOGIST 


C.   B.    SI^TPSOjST, 

Special  Field  Agent. 


WASHINGTON: 

GOVERNMENT    PRINTING    OFFICE. 
19  03. 


Bui  41.  New  Series.  Div.of  Entomology,  U.S.  Depr.of  Agriculture. 


Tin- dotted j/arttiiTUte  Austral  Zorues  i 
oftAe  tirvat  Phtins  indicate  the  extent  oftiir 
hamid  divisions  „ft7iese  Zones,  known  res,,ee 
tivcly  astne  ARjefftXajuan  Cnro/inzttn  and  Ans 
tj-orifariari  FaumtbS   TlU  Tmdotted.  /jar-ts  oTtfu- 

Zones  are.   knoM-n,  as  the  Transition 
t/pper  Sonoran  and  Zower  So? 


December,  1897. 


LIFE   ZONES  OF  THE  UNITED  STATES 

BY 

C.HART  MERRIAM 


U.  S.  DEPARTMENT  OF  AGRICULTURE. 

DIVISION  OF  ENTOMOLOGY— BULLETIN  NO.  41. 

L.    O.    HOWARD,    Entomologist. 


THE  CODLING  MOTH 


PREPARED  UNDER  THE  DIRECTION  OF  THE  ENTOMOLOGIST 


O.   B.   SIMPSON, 

Special  Field  Agent. 


WASHINGTON : 

GOVERNMENT    PRINTING    OFFICE. 

1903. 


n/Vlsmx  OF  ENTOMOLOGY 


I..  I  >.  I  l«»w  lbd,  Entomologist. 

C.  L.  M  \ki  \n,  in  charge  of  i  vperimental field  work. 

V.  II.  Chittenden,  mcharg\  of  breeding  experiments. 

A.  I).  Hopkins,  in  charge  of  forest  insect  investigations. 

Frank   Benton,  in  charge  of  apiculture. 

\\     l>.  Ih  nter,  '//  charge  of  cotton-boll  weevil  investigations. 

I  >.  W.  Coqdillett,  Th.  Peboandb,  Nathan    Hanks,  Assistant  Entomologists. 

E.  A.  Schwarz,  I"..  S.  «■.  Titus,  Investigators. 

Miss  II.  A.  Kelly,  Special  agent  in  silk  investigations. 

I;    8.  Clifton,   1".    C.   Pratt,   A.ugust  Bdsck,  Otto    Heidemann,   A.    N.  Caudell, 

.1.    KOTINSKY,    II.   <i.    BARBER,    Assistants. 

\V.  I..  1 1 1\!)-.  W.  I'.    Fiske,  A.  L.  Quaintance,  <i.  II.  Harris    11.  E.  Burke,  a.  W. 
Morrill,  Temporary  field  agents. 


LETTER  OF  TRANSMITTAL 


U.  S.  Department  of  Agriculture, 

Division  of  Entomology, 
Washington,  I).  C,  July  00,  1903. 
Sir:  I  transmit  herewith  the  manuscript  of  a  report  on  the  codling 
moth,  prepared  under  my  direction  by  Mr.  C.  B.  Simpson,  rield  agent 
of  this  Division.  Mr.  Simpson  had  been  charged  with  a  special  inves- 
tigation of  the  codling  moth,  more  particularly  in  the  Northwest,  in 
answer  to  special  requests  for  such  study  in  the  newly  developing 
fruit  interests  of  that  region.  The  codling  moth  is  undoubtedly  the 
most  important  insect  pest  of  apple  and  pear,  and  is  the  occasion 
of  greater  loss  than  all  the  other  insect  enemies  of  these  fruits  com- 
bined, entailing  an  annual  shrinkage  of  values  exceeding  $11,000,000. 
Mr.  Simpson's  investigations  covered  a  period  exceeding  two  years, 
and  have  already  been  voiced  in  a  small  preliminary  bulletin  and  in  a 
Farmers'  Bulletin  giving  condensed  advice  relative  to  the  control  of 
this  insect.  The  present  publication  is  the  final  and  complete  report, 
elaborating  all  of  the  conclusions  and  results  of  this  special  investiga- 
tion. It  will  be  a  very  useful  document  for  all  workers  in  applied 
entomology  and  of  decided  practical  value  for  the  fruit  groAver. 
The  illustrations  which  accompaiw  it  are  essential  to  the  correct 
understanding  of  the  experiments  reported  and  of  the  text.  I  recom- 
mend that  this  report  be  published  as  Bulletin  Xo.  41  of  the  Division 
of  Entomology.  As  stated  in  the  letter  of  transmittal  of  bulletin  No. 
10,  the  term  "New  Series"  has  been  dropped. 
Respectfully, 

L.  O.  Howard, 

Entomologist. 
Hon.  James  Wilson, 

Secretary  of  Agriculture. 

3 


CONTEXTS. 


Page. 

Introduction 9 

Systematic  position 10 

Names  of  the  insect 11 

Popular  names 11 

Scientific  names 11 

Varieties  of  the  codling  moth 11 

Geographical  distribution ' 13 

Relation  of  distribution  to  life  zones 14 

Boreal  zone 14 

Transition  zone _ 14 

Upper  Austral  zone 15 

Lower  Austral  zone 15 

Immune  regions 16 

Means  of  spread 16 

Estimated  losses 17 

Food  habits 18 

Fruits  infested 18 

Nat-feeding  hal  »its 19 

Leaf-feeding  habits 19 

Primitive  food  habits 21 

Work  of  other  insects 21 

Life  history .■ 24 

The  egg 24 

Places  where  laid 25 

When  cue  eggs  are  laid 26 

The  number  of  eggs  laid  by  one  female 26 

The  egg-laying  period 27 

Duration  of  egg  stage 27 

Hatching  of  the  egg 28 

Changes  during  incubation 28 

Methods  of  obtaining  eggs 29 

Influence  of  temperature  upon  the  length  of  the  ^gg  stage 29 

Mortality  among  the  eggs 30 

The  larval  stage 30 

Description  of  full-grown  larvae 31 

Entering  the  fruit 31 

Places  of  entrance : 12 

Time  spent  in  the  fruit 34 

Preparations  for  leaving  the  fruit 34 

Leaving  the  fruit 34 

Places  of  spinning  coec  K>ns 35 

Description  of  the  cocoon 36 

5 


6 

Life  history    ( Sontinued.                                                                  •  Page. 
The  larval  Btage    <  lontinued. 

I  Miration  of  the  Btagee  in  the  coc-.un :(>7 

[nfluence  of  temperature  upon  the  duration  of  the  stage 38 

Effect  of  the  insect  upon  the  fruil 39 

The  pupa 39 

Emergence  of  the  moth .°>9 

The  adull  insect 40 

1  low  to  distinguish  the  sexes 10 

Habits  of  the  moth 41 

Duration  of  life  of  the  moth 1 

<  fenerations  of  the  insect 41 

Sen-,  u ia I  history 50 

Emergence  of  the  moth 50 

Relation  between  the  emergence  of  the  moth  and  the  blooming  period...  51 

Hibernation 54 

Evidences  of  a  third  generation 55 

( 'oiiclusion 56 

Natural  conditions  which  tend  to  decrease  numbers 57 

Natural  enemies.    57 

I  inert  el  irate  enemies 59 

How  to  com  hat  the  insect 00 

Preventive  measures 00 

Setting  the  trees 62 

Pruning 68 

Irrigation (54 

Boil  or  cover  crops 04 

Orchard  in  bearing 04 

Preparing  fruil  for  the  market 65 

Preventive  measures  in  old  orchards. 07 

Treatment  of  old  orchards OS 

Remedial  measures 69 

Measures  of  little  or  no  value 69 

Measures  of  value 72 

Measures  used  against  the  larva 72 

Materials  for  Bpraying 80 

Cost  of  spraying 83 

Time  and  frequency  of  application  of  spray 85 

I  low  the  poison  kills  the  insect 86 

The  banding  system 88 

Expense  of  banding 91 

When  1-auds  may  be  used    92 

Practical  tests 92 

Resume*  and  conclusion *'0 

Bibliography  of  the  more  important  contributions  to  the  literature  of  the  cod- 
ling moth 97 


ILLUSTRATIONS. 


PLATES. 

Paere 

Pla  te  I.  Life  zones  of  the  United  States Frontispiece. 

II.  Fig.  1. — Apple  leaf  inhabited  by  codling-moth  larva.     Fig.  2. — Apples 

damaged  by  caterpillar 16 

III.  Eggs  of  the  codling  moth 16 

IV.  Fig.  1. — Entrance  holes  of  larvae  of  second  generation.     Figs.  2  and 

3. — Views  in  orchard  of  Hon.  Edgar-  Wilson 32 

V.  Fig.  1. — Codling  moth  larva,  enlarged  about  three  times.  Fig.  2. — 
The  "worm  hole"  or  exit  hole  of  the  apple  worm  (enlarged). 
Fig.  3.—  A  wormy  apple,  showing  the  familiar  mass  of  brown  par- 
ticles thrown  out  at  the  blossom  end  by  the  young  larva  (from 

Slingerlaud  ) 32 

VI.   Fig.  1.  —  Larvae,  pupa-,  and  moths  on  rough  bark.     Fig.  2. — Infested 

apples  being  rmr'ied 48 

VII.   Fig.  1. — Codling  moth  enlarged  four  times.      Fig.  2. — Codling  moths 

enlarged  twice.     Fig.  3. — Codling  moths,  natural  size 48 

VIII.  Stubs  of  branches  trom  an  old  orchard  near  Elkton,  Md.,  showing 

work  of  codling-moth  larvae  and  wo;  ulpeckers 64 

IX.  View  in  orchard  of  Hon.  Fremont  Wood,  near  Boise,  Idaho 64 

X.  Fig.  1. — Band  on  which  the  remains  of  330  cocoons  were  counted. 
Fig.  2. — Pupa  in  cocoon  on  underside  of  a  loose  piece  of  bark. 
Fig.  3. — Larva  and  pupae  in  cracks  in  bark  from  which  rough  bark 

has  been  removed 80 

XI.  Gasoline  power  spraying  machines 80 

XII.  Spraying  outfits  in  use 80 

XIII.  Clean  and  wormy  apples  from  tree  Xo.  2,  Wilson  orchard 96 

XIV.  Clean  and  wormy  apples  from  tree  No.  4,  Wilson  orchard 96 

XV.  Clean  and  wormy  apples  from  tree  No.  6,  Wilson  orchard 96 

XVI.  Preparing  apples  for  market,  orchard  of  Hon.  Fremont  Wood,  Boise, 

Idaho 96 

TEXT  FIGURES. 

Fig.     1.  Anarsia  lineatella 21 

2.  Plodia  interpunctella 22 

3.  Larverna  herellera 22 

4.  Nephopteryx  rubrizonella 23 

5.  Daily  band  record  made  by  II.  <r.  Gibson,  Nampa,  Idaho,  in  1901, 

upon  four  trees 46 

6.  Weekly  summary  of  Mr.  Gibson's  band  record 47 

7.  Band  record  made  by  William  A.  George,  Caldwell,  Idaho,  in  1901.  47 

8.  Weekly  band  record  made  by  Mr.  Ayrea  at  Boise,   Idaho,  in  1897, 

on  140  trees 48 


Page. 

9,   Band  record  made  by  Mr.  Ayres  in  L898 48 

10.  Band  record  made  by  David  Brothers  in  Colorado  in  L8J9 49 

11.  Band  record  published  by  Prof.  ('.  P.  Gillette,  taken  on  14  trees,  at 

Fori  Collins,  Colo.,  in  L900 49 

12.  Band  record  taken  by  E*rof.   E.  A.   Popenoe,  Manhattan,  (Cans.,  in 

I  smi  i 50 

13.  Band  record  made  by  Chapin  on  850  trees  in  San  Jose,  Cal 5] 

li.   Band  record  by  Prof.  ,1.  M.  Aldrich,  Juliaetta,  tdaho,  on  40  trees. 

L899 52 

16.  one- >!' the  records  made  by  II.  E.  Burke,  at  Boise,  [daho,  in  L902,  to 

det ermine  the  maximum  of  the  second  generation 52 

in.   Record  by  EL  C.  Close,  Utah  Agricultural  College 53 

1 7.  Spraying  outfit  for  treating  tall  trees ; 75 

18.  Large  apple  tree  properly  banded  for  the  codlingmoth  (original)...  89 
l(.i.   Apple  tree  banded,  showing  bands  both  above  and  below  a  hole  in 

the  tree 89 


THE  CODLING   MOTH 

( (  hrpocapsa  pomonella  Linn.) 


INTRODUCTION. 

Every  person  is  acquainted  with  "wormy  apples/'  and  many  have 
seen  the  caterpillars  in  the  fruit,  while-  few  know  the  history  of  the 
worm-like  creature  which  causes  the  injury,  or  whence  it  comes  or 
whither  it  goes. 

If  apple  insects  were  classified  in  the  order  of  the  degree  and  extent 
to  which  the}'  cause  monetary  loss,  the  codling  moth  would  rank  first, 
since  it  causes  more  injury  than  all  other  insect  enemies  of  this  fruit 
combined.  It  is  the  most  serious  drawback  with  which  the  apple  grower 
has  to  contend,  as  from  one -fourth  to  one-half  of  the  apple  crop  of  the 
United  States  is  injured  every  year.  The  control  of  this  pest,  how- 
ever, is  not  difficult  when  compared  with  that  of  many  other  insects, 
and  hosts  of  apple  growers  are  each  year  saving  practically  all  of  their 
crop  from  its  ravages. 

In  the  literature  of  the  subject,  one  finds  that  Cato  makes  the  first 
mention  of  this  insect,  and  since  that  time  almost  every  entomologist 
has  studied  it  and  written  about  it.  By  the  writings  of  LeBaron, 
Walsh,  Riley.  Cook,  Goff,  Forbes,  Howard,  Slingerland,  and  many 
others,  information  about  its  life  history  and  remedial  measures  lias 
been  disseminated,  which  have  facilitated  its  control  in  the  eastern 
part  of  the  United  States. 

It  was  found  that  in  the  western  United  States  the  conditions  were 
different  from  those  in  the  East  and  that  the  recommendations  which 
brought  success  in  the  East  did  not  give  satisfactory  results  in  the 
West,  and  the  necessity  arose  of  making  a  close  study  of  the  western 
conditions.  Among  those  who  have  written  on  the  insect  in  the  West 
are  Messrs.  Washburn,  Koebele,  Card,  Aldrich,  Gillette.  Cordley,  and 
Cooley. 

The  two  principal  accounts  of  this  insect  are  those  by  Dr.  L.  O. 
Howard  in  1888  and  Prof.  M.  V.  Slingerland  in  1898.  Both  of  these 
writings  give  a  summary  of  what  was  known  of  the  insect  at  those 
dates,  with  many  original  observations  and  suggestions  for  its  control. 


10 

Slingerland's  bulletin  is  especially  comprehensive,  partly  because  of 
the  late  date  <>t'  its  publication,  and  partly  because  a  complete  bibliog- 
raphyand  valuable  historical  notesare  given.  The  excellent  observa- 
tions and  photographs  arc  important  features  of  this  publication, 
which  has  been  of  t ho  greatest  assistance  t<>  the  writer  of  this  bulletin. 

The  writer  is  under  obligation  to  many  for  the  aid  given  in  this 
work.  Hon.  Edgar  Wilson,  Hon.  Fremont  Wood,  and  Mr.  W.  F. 
Cash  rendered  assistance  in  carrying oul  the  practical  tests;  Mr.  Alex. 
McPherson,  the  State  horticultural  inspector,  made  observations  and 
gave  aid  in  many  ways;  Mi*.  S.  M.  Blandford,  of  the  United  States 
Weather  Bureau,  at  Boise,  kindly  furnished  the  temperature  data  used; 
Mr.  II.  F.  Burke,  of  the  Department  of  Agriculture,  assisted  in  the 
work  in  L902,  and  did  much  valuable  and  accurate  work  upon  the  life 
history  of  the  insect;  Prof.  C.  P.  Gillette  and  Mr.  I).  W.  Coquillett 
kindly  gave  the  writer  access  to  their  notes.  Many  fruit  growers  in 
Idaho  have  rendered  especially  valuable  aid  in  keeping  records.  Pro- 
fessor Slingerland  granted  permission  to  use  many  of  his  figures,  and 
his  bibliography,  with  his  notes,  is  used  as  a  foundation  for  that  por- 
tion of  this  bulletin.  Prof.  J.  M.  Aldrich,  Prof.  A.  P..  Cordley,  and 
Prof.  C.  V.  Piper  have  at  all  times  given  aid,  counsel,  and  advice, 
and  granted  permission  to  use  their  unpublished  data. 

The  estimates  of  injuries  inflicted  by  the  codling  moth  given  in  this 
bulletin  are  based  principally  upon  observations  made  upon  check 
trees  in  Bpraying  experiments. 

SYSTEMATIC  POSITION. 

The  codling  moth  belongs  to  the  order  Lepidoptera,  or  scale-bear- 
ing insects,  and  has  been  assigned  to  the  family  Tortricida1.  The 
description  of  the  genus  Oarpocapsa  Treitschke,  as  given  by  Meyrick, 

i-  ;t-  follow-: 

Antennas  in  $  simple.  Palpi  moderate,  curved,  ascending.  Thorax  smooth. 
Fbrewings  with  termen  Blightly  sinuate.  Hindwings  in  $  with  longitudinal  groove 
below  cell,  including  a  hair  pencil;  3  and  t  connate  or  stalked.  .">  nearly  parallel  to 
1,  «>  and  7  closely  approximated  toward  l>ase.  A  small  hut  rather  widely  distributed 
genua.    *    *    * 

The  species  pomonetta  is  distinguished  from  the  other  species  by 

having  the  margin  of  the  ocellus  (or  black  spol  on  the  wing)  of  a 
coppery  metallic  color.  (See  1*1.  VII.)  The  description  of  poinonetta 
in  given  by  Meyrick  :»vs  follows: 

li  r.i  mill.     Porewings  dark   fuscous,   finely  irrorated  with  whitish,  with  darker 
basal  patch  sometimes  darker;  a  large  dark  coppery  brown  terminal  patch 
hardly  reaching  costa,  anterior  edge  more  blackish,  ocellos  within  this  edged  with 
bright  coppery  metallic.     Hindwings  fuscous,  darker  terminally. 


11 

NAMES  OF  THE  INSECT, 
POPULAR  NAMES. 

The  name  " codling  moth"  is  the  one  most  generally  used  by  the 
American  fruit  growers.  The  first  name  given  to  this  insect  was 
*'pear  eater."  on  account  of  its  feeding  in  pears.  Later  writers  called 
it  the  "apple  and  pear  worm  or  moth,''  "fruit worm,"  "fruit  moth," 
and  many  others  names.  The  name  "apple  worm"  is  often  used, 
especially  by  the  English. 

Wilkes,  an  English  author,  first  used  the  name  in  1747,  which  name 
was  taken  from  a  kind  of  apple  tree.  Slingerland  says  that  the  word 
"codling"  is  doubtless  a  corruption  of  the  old  English  word  "querd- 
lying,"  which  means  any  immature  or  half -grown  apple.  Some  hor- 
ticulturists and  entomologists  and  others  use  the  names  "coddling"  or 
"codlin."  As  a  result  of  extended  research  Slingerland  discards  these 
names  and  gives  the  name  "codling"  decided  preference. 

SCIENTIFIC  NAMES. 

In  1758  Linnaeus  gave  this  insect  the  specific  name  of  pomonella  and 
the  discription  is  as  follows:  "Alis  nebulosis  postice  macula  rubra 
aurea."  Schiffermulier.  1770,  named  it  "pomonana."  Fab  ricius.  1793. 
gave  it  the  name  "  pomona."  By  reason  of  the  eighteen  years  priority 
the  name  "pomonella"  stands. 

Linnaeus  gave  this  insect  the  generic  name  of  Tmea.  Later  it  was 
known  as  PyraHs^  Tortrix,  Semasia,  and  Erminea.  Still  later  it  was 
given  the  name  Carpocapsa,  which  was  in  use  for  about  three-quarters 
of  a  century.  In  1897  Walsingham  concluded  that  the  name  Carpocaj.  >sa 
must  fall  and  be  replaced  by  Cydia.  This  view  was  adopted  by  Fernald 
in  Dyar's  list  of  North  American  Lepidoptera;  but  Cockerell  strongly 
doubted  this  conclusion.  After  a  very  exhaustive  study  of  the  sub- 
ject Mr.  Busck  concludes  that  the  old  name  Carpocapsa  is  the  proper 
name  and  must  be  restored,  and  his  conclusions  are  accepted  in  this 
publication. 

VARIETIES  OF  CODLING  MOTH. 

Stand inger  described  a  variety  of  the  codling  moth  which  was  bred 
from  either  apple  or  walnut  in  which  the  coppery  spots  in  the  ocellus 
were  more  broken  and  gave  it  the  name  of  jmtaminana. 

It  has  evidently  been  thought  for  many  years  that  there  was  a 
variety  of  the  codling  moth  in  the  far  west.  Matthew  Cooke  said  in 
1883:  "From  investigation  it  is  probable  that  there  are  more  than  one 
species  of  codling  moth  infesting  the  fruit  of  this  State  [California], 
but  1  am  not  prepared  to  report  at  the  present  writing." 

In  1900  the  writer  found  one  buff-colored  moth  which,  except  for 
color,  was  like  the  common  codling  moth,  on  the  trunk  of  a  tree  at 


12 

Boise,  Idaho.  During  1901  four  well-preserved  specimens  and  eight 
badly  worn  specimens  were  secured.  In  L902  six  of  these  buff-colored 
moths  wore  bred  among  L82  normal  moths.  In  material  collected  in 
Idaho  in  the  fall  of  l'.xijj,  from  which  about  30  moths  emerged  the 
following  spring,  five  were  of  this  variety.  Mr.  A.  F.  Hitt,  of  Weiser, 
Idaho,  and  Mr.  Alex.  MePherson.  tell  the  writer  that  they  have 
noticed  these  buff-colored  moth-.  Mr.  Hitt,  in  L896,  bred  seven  of 
these  among  50  normal  moths. 

The  writer  submitted  the  moths  to  Mr.  August  Busck,  of  the  Tinted 
State-  Department  of  Agriculture,  for  determination,  and  in  the 
Proceedings  of  the  Entomological  Society  of  Washington  he  describes 
them  as  follows: 

These  Bpecimens  were  submitted  to  the  writer  for  determination,  and  I  have  care- 
fully examinedl  hem  structurally  in  comparison  with  the  common  form  of  Cydia{^) 
pomoneUa  Linne.  I  do  not  think  there  can  be  any  doubt  about  their  being  this 
Species;  the  "nil  parts,  the  venation,  the  secondary  male  sexual  character  of  the 
hind  wing,  and  the  external  sexual  organs  of  both  sexes  are  identically  as  found  in 
the  common  dark  form  of  the  codling  moth.  The  general  pattern  of  ornamentation 
is  also  the  same,  but  the  coloration  is  so  strikingly  different  that  the  variety  deserves 
a  special  name,  the  more  so  as  no  intermediate  forms  seem  to  occur.  I  propose 
that  it  l>e  known  as  Oydia  (M  pomoneUa  Linne,  var.  simpsonii. 

Instead  of  the  dark  fuscous  color  of  the  common  form,  the  variety  is  light  buff, 
With  slightly  darker  buff  transverse  striation.  In  the  common  form  the  forewings 
are  finely  irrorated  with  white,  each  scale  being  slightly  white  tipped;  in  simpsonii 
the  BCales  are  not  white  tipped.  The  terminal  patch,  which  in  the  common  form  is 
dark  coppery  brown,  nearly  black,  and  with  dark  violaceous  metallic  streaks,  is  in 
simps' ni ii  light  fawn  brown  with  pure  golden  metallic  streaks.  The  extreme  apical 
edge  before  the  cilia  is  in  the  common  form  black,  in  the  variety  reddish  brown, 
and  the  cilia  in  simpsonii  are  light  golden  ocherous  instead  of  the  dark  fuscous  of  the 
common  form.  The  head,  palpi,  body,  legs,  and  the  tuft  of  hairs  on  the  hind  wings 
of  the  male  are  correspondingly  light-buff  colored  in  the  variety  instead  of  dark 
foSCOOS,  as  in  the  common  form. 

Besides  Mr.  Simpson's  specimens,  in  which  both  sexes  are  equally  represented, 
there  is  in  the  United  States  National  Museum  a  single  female,  labeled  "Cook,  Cali- 
fornia. July  30,  1883." 

Type:    No.  6803,  United  States  National  Museum. 

The  writer  has  never  observed  any  gradations  between  this  variety 
and  the  common  form,  [t  is  most  probable  that  this  variety  is  dis- 
tinctly western,  as  there  are  no  records  of  its  having  been  bred  in  the 
East.  No  attempt  was  made  to  secure  the  earlier  stages  of  tin1  insect, 
and.  a>  far  as  observations  were  made,  its  life  history  IS  similar  to  that 
of  the  normal  form  of  the  codling  moth,  as  tin4  larvae  from  which  this 
variety  was  bred  were  taken  with  the  larva' of  the  normal  form  under 
bands  on  apple  trees.  One  might  theorize  On  what  conditions  in  the 
West  have  given  rise  to  this  new  variety,  but  to  state  with  any  degree 


"Tin-  generic  name  Cydia  used  by  Mr.  Busck  before  bis  investigations,  which 
resulted  in  the  restoration  of  the  old  name  ( hrpooapsa. 


13 

of  certainty  exactly  what  has  brought  about  this  change  is  impossible 
from  the  data  at  hand. 

GEOGRAPHICAL  DISTRIBUTION. 

The  original  home  of  the  codling  moth  is  not  definitely  known,  but 
is  supposed  to  be  southeastern  Europe,  the  home  of  the  apple.  It  has 
followed  the  distribution  of  the  apple  closely  until  it  is  now  present, 
with  but  few  exceptions,  in  all  countries  where  apples  are  grown.  It 
ha-  spread  over  Europe,  and  is  present  as  far  as  the  apple  region 
extends  in  Siberia.  It  was  noted  in  Australia  about  1855.  Tasmania 
about  1861.  New  Zealand  in  1871:,  South  Africa  about  1885,  and  Zeller 
received  it  from  Brazil  in  1891. 

Mr.  C.  L.  Marlatt  reports  that  he  did  not  observe  this  insect  in 
either  Japan  or  China  in  his  extended  travels  in  those  regions.  Mr. 
George  W.  Compere  also  states  that  he  has  never  observed  it  in  China. 
Prof.  A.  B.  Cordley  states  that  this  insect  has  reached  China.  Evi- 
dently some  correspondent  of  his  has  reported  it  as  present  in  that 
country.  As  apples  are  being  continually  shipped  to  both  Japan  and 
China,  it  is  but  a  question  of  a  few  years  when  it  will  either  be  intro- 
duced or  become  injurious  in  the  orchards  of  those  countries. 

Extended  researches  of  many  investigators  have  failed  to  give  date 
or  definite  information  as  to  the  time  and  manner  of  introduction  of 
the  codling  moth  into  America.  For  a  long  time  injury  to  the  apple 
by  this  insect  wa^  thought  to  be  the  work  of  the  plum  curculio;  and 
it  was  not  till  1819  that  the  codling  moth  was  reared  from  wormy 
apples  by  Burrell.  It  was  evidently  quite  well  distributed  in  the 
eastern  United  States  before  its  work  was  identified,  as  there  are  but 
few  records  of  its  spread.  In  181:0  it  was  a  serious  pest  in  New  Eng- 
land and  central  New  York.  About  1860  it  invaded  Iowa.  For  many 
years  it  has  been  a  serious  pest  in  Canada.  Mr.  Alexander  Craw 
stated  in  1893  that  the  insect  was  first  introduced  into  California  by 
means  of  some  fruit  brought  from  the  East  to  Sacramento  for  exhibi- 
tion purposes  in  1872.  No  measures  were  taken  to  destroy  the  insects 
in  this  fruit,  and  two  years  later  its  presence  in  abundance  was  noted. 
Later  it  was  rapidly  distributed  over  the  State,  aided  by  the  system  of 
returning  boxes.  Dr.  C.  V.  Riley  mentions  in  1876  that  this  insect 
was  then  present  in  Utah,  where  it  had  evidently  been  introduced  a 
year  or  two  previously. 

From  these  points  of  infestation  the  codling  moth  spread  over  the 
Western  States.  Prof.  J.  M.  Aldrich  states  that  it  has  been  known  in 
the  Clearwater  Valley  in  Idaho  since  1887.  Mr.  I.  L.  Tiner.  of  Boise, 
states  that  in  1887  he  found  the  first  indication  of  this  insect  at 
Boise.  Idaho.  Mr.  Thomas  Davis,  of  Boise,  states  that  it  was  intro- 
duced into  his  orchard  at  about  the  same  time. 


14 

RELATION  OF  DISTRIBUTION  TO  LIFE  ZONES. 

Although  the  codling  modi  muv  be  brought  into  a  section  ol  country, 
it  may  not  be  able  to  obtain  a  foothold  on  account  of  the  adverse  cli- 
mate. In  other  regions  it  is  never  very  injurious,  or  it  may  be  quite 
injurious  one  year  and  almost  absent  the  next;  hut  in  warmer  regions 
it  reaches  the  maximum  of  destructiveness. 

In  order  to  study  these  conditions  the  writer  has  used  the  life  zone- 

of   Dr.  C.  Hart    Merriam  (PI.    I).      Upon   consulting  this  map  one 

finds  that  there  are  seven  different  /ones  in  the  United  State-.  In 
the  eastern  portion  they,  in  a  general  way.  extend  east  and  west, 
while  in  the  western  part  they  are  broken  into  irregular  areas  by  the 
mountain  ranges.  There  are  many  important  subdivisions  of  these 
zones,  depending  principally  upon  the  amount  of  moisture  and  the 
milder  and  more  temperate  climate  near  the  seacoasts. 

BOREAL   ZONK. 

'The  principal  apple-growing  regions  of  this  zone  are  in  Nova  Scotia. 
northern  Maine,  northern  Michigan,  and  western  Oregon.     Except 

for  the  Pacific  coast  strip,  only  the  more  hardy  varieties  of  apple-  are 
grown  in  this  zone.  There  is  ;i  great  lack  of  definite  data  in  regard 
to  the  exact  amount  of  injury  the  insect  causes  in  this  zone.  As  near 
as  the  writer  can  learn,  the  injury  is  never  so  great  as  it  is  in  the  next 
warmer  zone.  According  to  Cordley,  the  insect  is  present  in  small 
numbers  in  the  Pacific  coast  strip  and  is  doing  but  a  comparatively 
small  amount  of  injury. 

TRANSITION    ZONE. 

The  transition  zone  includes  the  greatest  apple-producing  regions 
of  the  United  States,  the  A lleghenian  area  comprising  the  zone  in  the 
eastern  mountain  State-,  including  the  larger  part  of  the  apple-grow- 
ing regions  of  New  York,  Pennsylvania,  and  Michigan.  Although 
the  injury,  which  varies  with  the  seasons,  is  greater  in  the  transition 
than  in  the  boreal  zone  and  less  than  in  the  austral,  no  record  of 
definite  percentages  has  been  found  during  the  present  study. 

In  the  arid  area  of  the  transition  zone  the  loss  is  less  than  in  the 
Alleghenian  area.  Various  estimates  of  from  .~)  to  25  per  cent  <A' 
damage  have  been  given.  At  Moscow,  Idaho,  which  partakes  more 
of  the  1'acilic  coast  strip  characteristics  than  of  those  of  the  arid  area. 
Prof essor  Aldrich  records  the  amount  of  injury  as  21  percent  for 
I-:'1.'.  LO  percent  for  L900,  and  5  per  cent  for  L901.  Professor  Piper 
states  thai  in  L898  the  average  damage  about  Pullman,  Wash.,  was  LO 
per  cent,  and  some  orchards  were  injured  25  per  cent:  in  L902,  about 
5  per  cent.  Professor  Gillette  report-  from  35  t<>  so  per  cent  at  Fort 
Collin-.  Colo.,  varying  with  the  degree  of  infestation  in  the  Locality. 


15 

Cooley  reports  an  injury  of  95  per  cent  in  small  home  orchards  in 
Helena.  Mont.  There  are  many  regions  in  this  faunal  area  in  which 
the  insect  does  about  25  per  cent  damage,  and  for  some  reason,  prob- 
ably climatic,  the  injury  is  reduced  to  almost  nothing  for  several 
years,  after  which  the  numbers  of  the  insect  gradually  increase. 
Professor  Aldrich  records  that  in  1899  an  early  snowfall  and  low  tem- 
perature at  Moscow.  Idaho,  killed  a  great  many  of  the  larvae.  There 
are  many  other  localities  in  the  Pacific  Northwest  where  the  codling 
moth  either  has  not  been  introduced  or  has  not  thrived,  and  in  which 
the  injury  is  nominal. 

In  many  regions  where  the  transition  zone  is  pierced  by  valley-  of 
the  upper  Sonoran  zone  the  orchards  near  the  canyons  sutler  much 
greater  injury  than  those  more  remote  therefrom.  Professor  Piper 
has  noted  several  cases  in  which  this  was  true,  and  in  one  the  damage 
was  75  per  cent  or  over. 

THE    PACIFIC    COAST    TRANSITIONAL    AREA. 

This  area  includes  those  portions  of  Oregon  and  Washington  be- 
tween tin-  Coast  Mountains  and  the  Cascade  Range,  parts  of  northern 
California,  and  most  of  the  coast  region  of  the  State  from  near  Cape 
Mendocino  southward  to  the  Santa  Barbara  Mountains.  In  Oregon 
varying  percentages  of  injury  have  been  reported,  ranging  from  a  nom- 
inal los<  to  75  per  cent.  In  the  Hood  River  Valley  in  some  cases  it  is 
greater  than  this,  with  an  average,  perhaps,  of  about  2b  to  90  percent. 

UPPER    AUSTRAL    ZONE. 

The  upper  austral  zone  is  divided  into  two  areas  by  reason  of  the 
greater  humidity  of  the  eastern  portion. 

THE    CAROLINIAN    FACNAL    AREA. 

This  area  includes  the  great  apple  regions  of  the  Central  States  and 
many  smaller  portions  of  the  Eastern  States.  Many  entomologists 
have  reported  injury  in  these  areas  a-  ranging  from  3U  or  50  percent 
to  practically  100  per  cent. 

UPPER    SONORAN    FAUNAL    AREA. 

This  area  includes  that  portion  of  the  upper  austral  zone  west  of 
the  one  hundredth  meridian.  From  many  countings  and  estimates 
from  various  sources  we  tind  that  in  badly  infested  districts  the  injury 
varies  from  80  to  95  per  cent  under  normal  conditions,  and  it  is  very 
common  to  find  the  loss  reach  100  per  cent. 

LOWER    AUSTRAE    ZONE. 

In  this  zone  there  are  only  a  few  localities  where  apples  are  grown 
on  a  commercial   scale     Under  normal  conditions  in  badly  infested 


L6 

localities  the  Loss  is  almost  total.  Garcia  records,  from  check  tree- 
in  spraying  experiments,  that  the  loss  varied  from  67  to  99  percent. 
There  are  manj  localities  in  this  /.one  in  itoth  east  and  \se-t  where 
apple  can  be  grown,  l>nt  on  account  of  the  injuries  due  to  the  codling 
moth  other  crops  are  groiR  d  instead. 

IMMUNE  REGIONS. 

In  iiianx  regions  of  the  Far  West  one  often  hears  the  fruit  growers 
-m\  that  on  account  of  the  peculiar  climatic  conditions  of  that  region 
apples  are  free  from  injury  and  the  codling  moth  can  not  exist. 
Among  these  climatic  condition-  quoted  are  dense  fogs,  mountain 
breezes,  and  comparatively  high  altitude-.  Seven  or  eight  years  ago  it 
was  thought  that  the  Hood  River  Valley  was  immune  from  the  insect; 
the  same  was  thought  of  the  Pajora  Valley  in  California;  but  later 
development-  have  shown  that  immunity  was  due  to  the  fact  that  the 
insect  had  not  been  introduced  into  those  localities.  It  has  also  been 
.-aid  that  there  was  no  codling  moth  near  the  coast  in  Oregon,  but 
Professor  Cordley  finds  that  it  i-  present  in  some  localities  and 
believes  that  the  former  immunity  was  due  to  isolation. 

In  many  restricted  areas  in  the  Pacific  Northwest  more  or  Less 
isolated  the  codling  moth  i-  either  absent  or  present  in  such  small 
numbers  that  it  ha-  not  been  observed.  From  past  experience  and 
examination  of  these  Localities  it  is  evident  that  the  insect  in  its  gen- 
eral spread  has  not  yet  reached  them.  It  is  a  question  whether  or 
not  the  insect  will  be  injurious  in  these  localities,  but  it  is  certain  that 
it  can  be  present.  The  writer  has  no  hesitancy  in  concluding  that 
there  is  no  region  in  the  Pacific  Northwest  in  which  apples  are 
grown  in  which  the  codling  moth  can  not  exist. 

Many  causes  of  immunity  by  isolation  in  river  valleys  have  been 
noted.  The  most  marked  case  is  at  Mr.  I.  B.  Perrine's  orchard  at 
Blue  Lake.  Idaho.  The  nearest  orchard  is  L8  mile-  distant  down 
Snake  River,  while  there  are  no  orchards  in  the  other  direction  inside 
of  75  to  80  mile-.  This  orchard  wa-  free  from  codling  moth  until 
three  <>r  four  years  ago,  the  larvae  baving  undoubtedly  been  intro- 
duced  in  old  apple  boxes  about  that  time. 

MEANS   OF  SPREAD. 

There  are  -<i\  era!  way-  in  which  the  codling  moth  can  be  distributed. 
The  most  prolific  source  of  distribution  comes  from  the  shipping  of 
fruit  from  an  infested  region.  Fruit  which  contains  the  larval  insects 
ui:i\  be  shipped  great  distances,  and  when  the  larvae  complete  their 
growth  they  spin  cocoon-,  and  in  due  time  the  moth-  emerge,  and 
with  unerring  instinct  Beek  the  nearest  apple  trees.  Many  larvae  are 
found  t"  have  spun  their  cocoon-  in  the  angles  and  crack- of  the  boxes 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  II. 


q-     ^ 


Fig.  1.— Apple  Leaf  Inhabited  by  Codling  Moth. 

a,  Point  where  larva  entered  midrib,  at  junction  with  one  of  the  principal  veins;  b,  portion  of 
burrow  exposed  (photograph  by  Prof.  A.  B.  Cordley). 


Fig.  2 —Apples  Damaged  by  Unknown  Caterpillar. 
(Reduced  from  photograph  by  the  author.) 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agricultur 


Plate 


Eggs  of  the  Codling  Moth. 

Natural  size  of  eggs  at  a  and  6;  e,  showing  red  ring  in  egg:  et,  egg.  showing  the  hole  through 
which  the  larva  emerged:  h.  showing  the  egg  enlarged,  with  the  larva  inside:  <>.  the  end  of 
the  ovipositor  of  the  female.     (From  Slingerland.) 


17 

or  barrels.  In  many  localities  it  has  been  the  practice  to  return  to 
the  fruit  grower  for  refilling  boxes  in  which  fruit  has  been  marketed. 
This  practice  has  supplied  the  means  of  rapid  distribution  in  such 
ocalities. 

If  infested  fruit  is  shipped  any  distance  in  cars  the  larvae  spin  their 
cocoons  in  cracks  and  holes  in  the  walls  of  the  car  and  may  be  carried 
great  distances  before  the  moths  emerge.  This  is  thought  to  have 
been  the  source  of  the  infestation  at  Kalispell,  Mont. 

When  apples  are  stored  by  commission  houses  the  larva?  may  crawl 
into  boxes  or  cases  of  various  kinds  of  merchandise  and  thus  be  widely 
distributed. 

In  sections  where  the  orchards  are  near  each  other  the  spread  is 
accomplished  by  the  moth  flying  from  one  to  another;  but  when  they 
are  many  miles  apart,  which  is  especially  the  case  in  the  Far  West,  this 
means  of  distribution  doubtless  has  little  influence.  The  insect  can 
probably  fly  a  few  miles  with  the  aid  of  the  .wind,  but  ordinarily  4  to  0 
miles  from  a  source  of  infestation,  over  unimproved  land,  gives  partial 
if  not  complete  immunity. 

We  have  no  authentic  record  of  the  distribution  of  the  codling  moth 
with  nursery  stock,  but  one  can  readily  see  how  this  could  occur,  as 
the  larvae  might  be  in  the  cracks  in  the  ground  around  the  trees  or 
night  crawl  into  the  packing  and  thus  be  carried  great  distances. 

ESTIMATED  LOSSES. 

Of  all  the  insects  affecting  the  apple  the  codling  moth  causes  the 
greatest  loss,  and  many  estimates  have  been  made  of  the  damage.  In 
1889  Professor  Forbes  indicated  an  annual  loss  in  the  State  of  Illinois 
of  82,375,000.  It  is  estimated  that  in  1892  the  insect  caused  $2,000,000 
loss  in  Nebraska.  Professor  Slingerland  estimated  that  in  1897  the 
insect  taxed  the  apple  growers  of  New  York  $2,500,000  and  the  pear 
growers  $500,000.  In  1900  one-half  of  the  crop  of  Idaho  was  dam- 
aged, while  in  1901  the  loss  was  much  greater.  Mr.  McPherson  esti- 
mated the  loss  in  Idaho  in  1902  as  $250,000.  In  many  sections  of  the 
Pacilic  Northwest  the  annual  loss  is  from  50  to  75  per  cent. 

From  the  nature  of  the  case  it  is  most  difficult  to  estimate  the  annual 
loss  in  the  United  States  on'account  of  the  many  factors  which  enter 
into  the  problem.  By  taking  the  estimates  of  the  annual  crops  of 
apples  as  given  by  the  American  Agriculturist,  it  is  found  that  for  the 
years  1898, 1899,*1900,  1901,  and  1902  the  average  crop  was  47,000,000 
barrels.  From  1896  to  1902,  inclusive,  the  average  price  at  New  York, 
Boston,  and  Chicago  on  October  20  of  each  year  did  not  exceed 
$2.     Allowing  $1  for  packing,  transportation,  and  other  charges,  for 

«The  estimates  under  this  heading  have  been  revised  from  the  original  figures 
given  by  the  author  to  correspond  with  the  latest  data. — C.  L.  M. 
65U— So.  41—03- — 2 


is 

IT. ».<»<»<»  barrels  at  *1  we  have  a  cash  valuation  of  147,000,000  for 

the  first  and  second  qualities. 

It  i  w  ell  w  ithin  the  Limits  of  safety  to  estimate  that  one-fourth  more 
apples  would  have  been  placed  on  the  market  had  it  not  been  for  the 
codling  moth.  This  one-fourth  would  he  a  hoi  it  L2,000,000  barrels,  and 
would  have  no  value  except  for  cider  or  local  sale  at  very  low  price. 
'The  average  price  for  cider  apples  is  about  30  cents,  which  price  would 
yield  a  total  of  aboul  13,600,000  as  the  value  of  the  windfalls,  culls, 
and  cider  apples,  while  if  they  were  average  apples,  at  si  net  per  barrel 
the  value  would  he  $12,000,000,  showing  an  annual  loss  of  about 
$8,400,000.  The  loss  in  home  orchards,  in  which  the  percentage  of 
1<>—  i-  far  greater  than  in  the  commercial  orchards,  is  estimated  at 
$3,000,000,  giving  a  total  annua!  loss  of  Si  L,400,000. 

The  loss  in  the  country  at  large  or  any  section  of  the  country  will 
vary  with  the  size  of  the  apple  crop.  In  years  of  full  crops  the  com- 
parative injury  is  not  so  great  as  in  years  when  the  crop  is  small  and 
the  prices  high. 

FOOD  HABITS. 

This  insect  is  essentially  a  feeder  upon  rosaceous  fruits,  and  to  them 
all  of  the  injury  is  done. 

FRUITS  INFESTED. 

The  apple  is  hy  far  the  most  infested  fruit.  It  is  the  natural  food 
of  the  codling  moth,  and  under  ordinary  circumstances  is  the  only  fruit 
injured,  save  pears.  It  is  quite  safe  to  assume  that  the  larva1  of  the. 
codling  moth  originally  fed  upon  the  leaves  of  the  apple  and  that  the 
habit  of  burrowing  in  the  fruit  is  acquired.  Much  has  been  said  and 
written  as  to  the  resistance  by  different  varieties  of  apple  to  this  insect. 
In  Bulletin  35,  new  scries.  Division  of  Entomology,  the  writer  gave  a 
List  of  varieties  and  indicated  the  resistance.  It  is  a  notable  fact  that 
the  summer  varieties  of  apples  are  very  attractive  to  the  second  gen- 
eration of  insects.  Varieties  which  are  fragrant, as  the  Pewaukeeand 
Ortley  (Bellflower),  are  always  badly  infested.  As  a  general  rule,  one 
can  Bay  that  the  harder  and  less  ripe  late  apples  are  not  attacked  to 
the  same  extent  as  those  which  are  ripe  and  fragrant  when  the  second 
generation  enters. 

It  i-  impossible,  from  the  nature  of  the  case,  to  determine  the  exact 
ratio  of  resistance  of  the  varieties.  In  one  orchard  one  will  find  fruit 
of   the    Ben    Davis  variety  least    infested,  while   in   another   it    will    he 

the  most  infested.     These  differences  are  without  doubt  due  to  local 
conditions  in  the  different  orchards. 

Tear- are  next  in  order  of  infestation.  Under  ordinary  conditions 
they  are  not  injured  to  any  great  extent.  In  the  Pacific  Northwest  in 
badlj  infested  localities  the  injury  rarely  reaches  a  total  of  20  per  cent. 
When  remedial  measures  are  used  this  is  reduced  to. from  5  to  L5  per 


19 

cent.  Several  pear  orchards  have  been  noted  which  were  located  in 
neglected  orchards  in  which  there  were  few  or  no  apples.  The  second 
generation  of  the  insect  seemed  to  concentrate  its  destructiveness  on 
the  pears,  and  in  one  case  fully  80  per  cent  and  in  another  about  50  per 
cent  were  injured.  One  fruit  grower  in  Texas  reports  an  injury  of  50 
per  cent. 

Crab  apples  are  not  usually  so  badly  infested,  but  instances  have 
been  observed  where  they  suffered  fully  as  much. 

Many  records  also  show  that  peaches,  prunes,  plums,  cherries, 
quinces,  and  apricots  are  infested  by  the  codling  moth,  but  under 
ordinary  conditions  their  injury  amounts  to  practically  nothing.  In 
cases  where  there  is  a  lack  of  apples  and  the  infestation  is  very 
abundant  considerable  damage  results.  There  are  records  of  4o  per 
cent  injury  to  peaches  where  the  trees  were  quite  near  an  apple  house 
in  which  infested  fruit  was  stored. 

NUT-FEEDING  HABITS. 

There  are  several  European  records  of  this  insect  in  walnuts  and 
oak  galls.  In  1887  Dr.  Howard  carefully  sifted  these  reports,  and 
concluded  that  the  evidence  was  not  sufficient  to  definitely  prove  that 
the  insect  ever  feeds  upon  either  walnuts  or  oak  galls:  and  it  was 
highly  probable  that  the  larvae,  if  they  were  larvae  of  the  codling 
moth,  went  into  the  latter  for  the  purpose  of  spinning  their  cocoons. 

In  1895  Mr.  Adkin  exhibited  a  specimen  of  ft  yorrumdla  which  was 
bred  from  a  species  of  chestnut,  and  in  1896  gave  details  as  to  rearing 
this  insect  from  walnuts,  and  offers  the  explanation  that  these  nuts 
bear  fleshy  coats,  or  that  the  insect  was  originally  a  nut  feeder. 
Theobald  in  1896  wrote  that  in  his  investigations,  extended  over  many 
years,  he  had  never  himself  bred  Oarpocapsa pomoneUa  from  walnuts, 
but  had  found  both  ft.  gplendana  and  Plodia  interpuTicteUa.  Mr.  West 
stated  that  he  had  also  bred  the  insect  from  chestnut. 

Dr.  Riley  in  1869  recorded  that  he  had  a  specimen  of  a  moth  which 
had  been  bred  from  the  sweetish  pulp  of  a  species  of  screw  bean 
(Strombooarpa  monoica)  obtained  from  the  Kocky  Mountains.  Pro- 
fessor Cockerell  raises  the  question  of  the  correctness  of  this  record. 
In  1894  Professor  Bruner  reported  that  it  is  highly  probable  that  the 
insect  feeds  in  the  seed  buds  of  roses.  In  1901  the  writer  carefully 
searched  over  many  hundreds  of  these  seed  buds  of  roses  near  a  badly 
infested  orchard,  and  did  not  succeed  in  finding  a  single  one  that  wa- 
in any  way  injured  by  the  codling  moth. 

LEAF-FEEDING  HABITS. 

Professor  Card  in  1897  recorded  that  the  young  larvae,  especially  in 
confinement,  nibbled  portions  of  the  leaf.  The  writer  has  noticed 
many  times  leave-  that  had  been  eaten  where  he  thought  the  work 


20 

was  done  by  this  insect.  Professor  Cordley  has  succeeded  in  making 
some  observations  upon  this  leaf-feeding  habit  which  are  of  great 
value,  [n  a  recent  Letter  to  the  writer  he  details  his  experiences  as 
follows: 

It  wan  found  on  June  I  thai  these  eggs  had  hatched  and  nearly  all  of  the  larva-  were 
dead.  Two  of  them,  however,  had  fed  upon  the  leaves,  were  yel  alive,  and  had  made 
some  growth,  notwithstanding  the  fad  that  the  leaves  had  Keen  taken  from  the  tree 
nearly  a  month  before  and  were  therefore  presumably  no1  in  the  most  palatable  <  o  - 
dition.  Both  larvae  were  feeding  upon  the  lower  parenchyma  of  the  leaf,  and  one 
had  completely  covered  itself  with  a  web  holding  pellets  of  trass.  A  recently  hatched 
larva,  mounted  in  balsam,  measured  L.35  mm.  in  length;  the  larger  of  these  two 
larvae  at  this  time  measured  l.so  mm.  in  length  and  was  proportionately  stouter. 
Both  were  transferred  to  fresh  leaves,  upon  which  they  fed  until  June  S,  when  one 
of  them  disappeared.  The  other  continued  to  feed  until  June  1 1,  when  it  too  disap- 
peared. However,  1  noticed  a  slight  discoloration  of  the  midrib  of  the  leaf,  near 
w  here  this  larva  had  been  feeding,  and  on  carefully  opening  it  found  the  larva  feeding 
as  a  miner,  it  ha\  Lng  already  excavated  a  tunnel  about  L5  nun.  long.  I  then  examined 
the  other  leaf,  in  which  I  found  the  Larva  that  had  disappeared  three  days  before 
likew  ise  feeding  in  the  interior  of  the  midrib.  The  larva-  were  again  transferred  to 
fresh  leaves,  and  by  the  folio  wing  morning  each  had  again  disappeared  with  in  a  midrib. 
Both  larva?  continued  to  feed  within  the  midribs  until  June  16,  when  one  of  them, 
on  being  transferred  to  a  fresh  leaf,  refused  to  eat  and  soon  died.  The  other,  with 
occasional  changes  to  new  pastures,  continued  to  thrive  until  June  2-"),  when  it  was 
plump  and  active  and  apparently  in  the  best  of  health  and  spirits.  Unfortunately 
I  was  then  absent  from  the  laboratories  for  some  days,  and  when  I  returned  the 
larva  was  dead.  I  believe  that  with  careful  attention  it  could  have  been  brought  to 
maturity  on  a  diet  of  leaves  alone.  When  one  considers  that  it  lived  and  grew  for 
more  than  three  weeks  upon  leaves  thai  had  bem  severed  from  the  tree  sometimes 
for  several  days,  and  that  it  was  apparently  more  thrifty  between  June  1(>  and  25 
than  in  the  earlier  days  of  its  existence,  one  must  acknowledge  that,  while  the  proof 
is  by  no  means  positive,  the  indications  are  that  codling  moth  larva-  may  fully 
develop  on  a  diet  of  perfectly  fresh  apple  leaves  without  ever  having  tasted  fruit. 
PI.  II.  fig.  1.) 

The  writer  has  many  times  taken  larvae  from  apples  and  placed 
them  upon  Leaves  in  cages  and  bottles.  It  was  found  that  the  larvae 
would  fasten  the  leaves  together  with  silk  and  oat  holes  in  them;  but 
on  account  of  lack  of  attention  no  Larvae  were  bred  to  maturity.  The 
writer  believes,  and  agrees  with  Prof essor  Cordley  in  believing,  that 
the  larvae  with  proper  care  can  be  brought  to  maturity  on  the  leaf 
diet  ahuie. 

This  question  of  the  Leaf-feeding  habit  of  the  codling  moth  is  one  of 

the    most    Important    questions    in    the    life   history  of   the   insect,   and 

should  especially  commend  itself  to  entomologists  for  future  investi- 
gation, since  not  only  will  it  give  us  a  very  important  biological  fact, 
but  it  will  also  prove  very  definitely  how  spraying  i-  effective  against 
the  insect. 

It  ha-  often  been  recorded  that  larvae  gnaw  cavities  in  rough  rotten 
wood,  bark,  cloth,  paper,  and  other  places  where  they  spin  cocoons, 
and  the  bit-  of  these  substances  incorporated  in  the  cocoons.     From 


121 


observation  it  is  evident  that  the  larva*  do  not  eat  any  of  these  sub- 
stances. When  Paris  green  was  placed  under  the  band-  and  on  the 
bark  and  in  other  place-  where  the  larvae  spin,  it  was  found  that  none 
were  killed,  even  when  the  poison  was  abundant,  which  tend.-  to  show 
that  they  do  not  eat  of  these  snbstanc 

PRIMITIVE  FOOD  HABITS. 

Writer-  have  indulged  in  speculation  a-  to  the  primitive  food  habit 
of  this  insect.  The  other  species  of  the  genu-  arc  nut  feeder-,  and 
Adkins  expresses  the  opinion  that  this  insect  was  originally  such,  and 
that  the  habit  of  eating  apples  was  acquired. 

The  older  writers  have  said  that  the  insect  was  probably  a  leaf 
feeder.  From  the  experience  of  Professor  Cordley  this  view  appears 
to  be  the  more  probable  one. 

WORK  OF  OTHER  INSECTS. 

There  are  many  other  insects  which  feed  on  apples  whose  work  may 
be  taken  for  that  of  the  codling  moth  by  those  who  are  not  familiar 
with  the  characteristics  of  the  respective  insect-:  but  in  all  instances 
there  are  differences  in  the  work  and  habits  of  the  insects  by  which 
they  may  be  easily  distinguished. 

The  apple  maggot  (  TrypetapomoneUa). — This  insect  is  quite  injuri- 
ous in  the  northeastern  States,  and  its  work  in  the  apple  is  characterized 
by  many  winding  tunnels  through 
the  fruit.  The  larva  is  footless, 
and  ha-  no  distinct  head,  but  tapers 
toward  the  front.  This  maggot  i- 
the  early  stage  of  one  of  the  two- 
winged  flies. 

The  peach  twig-borer  (Anarsia 
Mneatdla). — Injury  to  peache-  and 
plums  by  this  insect  is  often  at- 
tributed to  the  codling  moth,  a-  it- 
second  generation  feed-  in  the  fruit. 
The  larvae  are  much  darker  red  and 
much  smaller  than  those  of  the  cod- 
ling moth,  and  the  mature  larva 
tapers  toward  either  end  (tig.  1). 

The  plum  curcalio  (Conotrachelus  nenuphar). — This  insect  often 
attacks  apples,  but  can  be  easily  distinguished  by  the  crescent— haped 
scar  made  in  egg  laying,  by  the  small  puncture-  caused  by  tin1  adult 
in  feeding,  and  by  the  fact  that  the  larva,  though  it  has  a  distinct  head. 
is  footless. 

The  Tndian-meal  moth  (Plodia  irderpwncteUa). — This  insect  feeds 
upon  edibles  of  nearly  all  kinds — meal,  grain,  seeds,  nuts,  dried  fruit-. 


Fig.  1. — Anarsia  UneateUa:  a.  twig  of  peach, 
showing  in  crotch  minute  masses  of  chewed 
hark  above  larval  chambers:  h.  latter  much 
enlarged:  c,  a  larval  cell,  with  contained  larva, 
much  enlarged:  <7.  dorsal  view  of  young  larva, 
more  enlarged  |  from  Marlatt  ■. 


00 


etc.  There  is  a  common  notion  among  some  farmers  that  the  larva  of 
this  insect  is  that  of  the  codling  moth,  and  the  writer  lias  often  been 
told  that  the  codling  moth  was  introduced  by  its  larvae  being  imported 

in  dried  fruit.  We 
have  no  reliable  rec- 
ords of  the  codling 
moth  having  ever 
eaten  dried  fruit, 
and  the  Indian-meal 
moth  is  the  princi- 
pal insect  that  has 
been  reared  from 
such  sources.  The 
caterpillar  is  much 
smaller  than  that  of 
the    codling    moth. 


l.—Plodia    irUcrptmcteUa;   a,  moth:   h.  chrysalis;    c,  caterpillar; 
in.'.  <l<>t^;il    view— eomewhal    enlarged;   '/.  head,  and   <.  firsl 
abdominal  segmenl  <>t'  caterpillar— more  enlarged  (from  Chitten- 
den . 


and   can  be  easily  distinguished  from   it  (tie-.   2). 

Th<   apple  fruit-miner  (Argyresthia  conjugeUa). — The  larva  of   this 
insect  has  been  found  attacking  apples  in  British  Columbia,  and  injuries 
which  may  have  been  caused  by  it  have  been  noted  in  Washington, 
Idaho,  and  Montana.     The  larva'  art1  about 
one-fourth  of  an  inch  in  length,  are  of  a 
dirty  white  color,  tinged  with  reddish  when 
full  grown,  and  taper  at  each  end.     The 
tunnels  made  in  tin1  fruit  are  numerous, 
ami  extend  in  all  directions. 

There  are  two  species  of  Lepidoptera 
which  do  great  damage  to  apples  in  Japan, 
which  may  sooner  or  later  succeed  in  en- 
tering this  country. 

Appli  fruit-borer  (L<"',  rna  hereUera), — 
This  insect  i-  said  to  have  gained  a  foot- 
hold in  British  Columbia.  The  larvae  live 
only  at  the  core  of  the  fruit,  injuring  the 
seeds.  When  full  grown  they  make  a  pas- 
sage  «>ut.  <rawl  or  drop  to  the  ground,  and 
-pin  a  white  cocoon  in  the  earth.  They 
hibernate  a-  pupa1,  and  there  is  only  one 
generation  each  year.  The  specie-  i- 
-how  ii  in  fig,  3,  which  also  illustrate^  its 
manner  of  work. 

Pear  fruit-borer  (Nephopteryz   rubizoneUa.)     It    is   stated    that    in 

Japan  the  pear  crop  is  injured  to  the  extent  of  :•>« >  to  50  pel'   cent    each 

year  bj  this  insect.      The  eggs  are  laid  in  clusters  on  the  twigs  and 


8.— Laverna  hereUera:  a.  adult; 
/<.  same,  si<lc  view;  <•,  larva:  <i,  co. 
coon;  '.  injured  apple— all  Blightly 
enlarged  except  < .  which  fa  reduced 

i  redrawn  from  liatsumura). 


23 


b 


leaves,  the  larva  making  its  way  thence  to  the  nearby  fruits,  which  it 
enters.  The  principal  work  is  around  the  core  of  the  pear.  The 
larval  stage  lasts  three  weeks  or  more,  and  the  pupal  stage  is  passed 
within  the  fruit.  The  insect  hibernates  in  the  egg  stage.  The  moth, 
larva,  and  pupa  are  illustrated 
by  tig.  4. 

Unknown  caterpillar  working 
on  out<  r  surface  of  apples. — 
Opportunity  is  taken  of  pre- 
senting the  reproduction  of  a 
photograph  of  apples  injured 
by  an  insect,  which  in  its  larval 
stao-e  somewhat  resembles  the 
codling  moth,  but  which  we 
have  as  yet  failed  to  rear  and 
identify. 

The  injury  was  first  brought 
to  the  attention  of  the  Division 
of  Entomology  by  Mr.  D.  W. 
Coquillett  in  October.  1901. 
The  apples  furnished  were  pur- 
chased in  open  market  in  the 
city  of  Washington.  The  in- 
jury appeared  to  be  almost  ex- 
clusively on  the  outer  surface, 
consisting  in  the  cutting  away 
of  the  skin  and  disfigurement 
of  the  apples  and  considerably 

depreciating  their  value  as  salable  articles  (see  PL  II,  fig.  2).  In 
some  cases  holes  entering  the  fruit  to  the  depth  of  about  one-fourth  of 
an  inch  were  found;  in  one  apple  to  the  depth  of  one-half  inch.  In 
November  Dr.  L.  O.  Howard  also  furnished  specimens  of  apples 
showing  injury  by  the  same  species.  One  of  the  larva1  spun  up  and 
formed  a  cocoon  November  6.  Unfortunately  all  the  larva1  died  with- 
out our  securing  the  moths.  The  following  brief  description  of  the 
larva  was  made: 

Reddish  flesh-colored,  head  dark  brown,  central  portion  of  face  whitish  and  trans- 
parent, with  two  black  spots;  cervical  shield  transparent,  except  for  caudal  margin 
Three  seta?  on  the  pre-spiracnlar  tubercle.     Length,  five-eighths  of  an   inch  when 
spinning  cocoon. 

It  will  be  noted  that  the  injury  illustrated  and  described  is  quite 
different  from  that  mentioned  and  figured  on  pages  87  and  88  of  Bul- 
letin No.  lo  (new  series)  of  the  Division  of  Entomology. 


Fn;.  L — Neph&pteryx  rvbrizonella:  adult  above,  larva 
just  beneath,  egg  mass  on  twig  at  right:  damaged 
pear  with  pupa  at  left— all  natural  size  (redrawn 
from  Matsumura  . 


24 

LIFE  HISTORY. 

Of  .-ill  insects  the  codling  moth  bas  the  largest  number  of  biog- 
raphers. It  bas  been  studied  in  nearly  every  country  in  the  world 
and  in  all  climates  in  which  it  exists.  The  early  accounts  were  always 
more  or  less  vague  and  inexact  and  gave  rise  to  many  false  ideas. 
Gradually  these  points  were  worked  out  until  to-day  we  can  say  that 
the  life  history  of  the  insect  is  as  well  if  not  better  known  than  that 
of  any  other.  Vet.  with  all  the  knowledge  we  have  of  it.  there  remain 
several  important  points  to  be  determined  by  future  work. 

It  i-  a  fundamental  principle  of  economic  entomology  that  in  order 
to  successfully  combat  an  insect  the  life  history  of  that  insect  must  be 
given  a  keen,  searching  study.  With  few  exceptions  these  studies 
peveal  BOme  point  in  the  life  of  the  insect  at  which  it  is  vulnerable 
to  preventive  <>r  remedial  measures.  Without  this  knowledge  efforts 
are  wasted  and  in  some  cases  are  a  positive  aid  to  the  insects.  It  can 
not  be  too  strongly  urged  that  each  fruit  grower  make  himself  familiar 
with  the  life  history  of  the  codling  moth  from  personal  observation, 
for  by  doing  so  be  is  placed  in  a  position  to  understand  the  reasons  for 
measures  of  control  and  to  exercise  his  ingenuity  in  applying  the  same 
to  his  own  orchard. 

The  ease  with  which  collections  can  be  made4  in  the  larval  stage  and 
the  accessibility  of  literature  pertaining  to  it  should  specially  com- 
mend this  insect  to  teachers  as  a  subject  for  nature-study  lessons. 

In  the  present  studies  upon  this  insect  particular  care  has  been  taken 
to  keep  the  different  stages  under  observation  in  exactly  the  same  con- 
ditions of  temperature,  moisture,  and  light  as  were  present  in  the 
orchard  in  which  the  cages  were  located,  and  as  a  result  the  writer  is 
able  to  present  some  definite  data  in  regard  to  the  effect  of  temperature 
upon  the  length  of  the  stages  of  the  insect  under  normal  conditions. 

A.8  in  other  lepidopterous  insects,  the  life  of  the  codling  moth  is 
divided  into  four  distinct  stages-  Qgg:  larva,  pupa,  and  adult.  In  the 
winter  and  early  spring  the  larvae  may  be  found  in  their  cocoons  in 
various  places,  as  in  cracks  and  holes  in  the  trees.  Later  the  larva 
transforms  into  a  pupa,  and  this  in  turn  changes  to  a  moth,  which  in 
turn  lays  eggs. 

THE  EGG. 

Since  the  time  of  Kocscl  many  authors  have  mentioned  the  egg  of 
the  codling  moth  and  stated  where  it  was  laid,  but  it  was  as  late  as 
1893  that  it  was  first  accurately  described  and  figured.  In  L874  Mr. 
W.  II.  Iliiilbnt  described  the  egg  as  being  about  one-eighth  of  an  inch 
in  length  and  nearly  white.     Riley  described   it  as  being  very  small 

and  of  a  yellow  color.  Messrs.  A.  ,1.  Cook.  Koebele.  Weir,  and  others 
undoubtedly  siw  the  eggs,  but  Cook  in  L881  and  Miss  M.  Walton 
doubtless  -:i\\    the  eggS  Of  SOme  other  insect. 


25 

In  1893  Professor  Washburn  gaye  an  accurate  description  of  the 
ego-,  with  the  first  figure  of  it.  This  figure  shows  a  well-formed 
embryo  inside,  but  the  network  of  ridges  near  the  center  is  much  too 
open. 

Slingerland  in  1896  and  Card  in  1897  distinguished  the  eggs  and 
made  many  observations  which  added  materially  to  our  knowledge  of 
this  stage.  In  his  1898  bulletin  Slingerland  publishes  many  excellent 
photographs  and  descriptions  which  caused  the  eggs  to  be  familiar 
objects.  Influenced  by  Slingerland's  and  Card's  work.  Aldrich,  Cord- 
ley.  Gillette,  and  others  have  from  time  to  time  added  to  the  sum  of 
our  knowledge  of  this  stage  of  the  insect.  It  is  remarkable  that,  in 
spite  of  the  many  studies  of  its  life  history,  the  egg  escaped  notice 
for  so  long  and  when  seen  was  not  described  and  figured  until  a  com- 
paratively late  date. 

The  egg  is  a  flat,  somewhat  oval-shaped  object  with  a  flange  around 
it.  It  varies  in  size  from  0.96  to  1  by  1.17  to  1.32  mm.  Commonly 
speaking,  it  is  about  the  size  of  a  pin  head.  The  surface  is  covered 
with  a  network  of  ridges  which  are  much  closer  together  toward  the 
central  portion  than  around  the  edge.  The  color  depends  upon  the 
age  of  the  embryo:  as  when  the  egg  is  first  laid  it  is  of  a  pearly  white 
color,  sometimes  with  a  decided  yellowish  tinge:  later  it  is  darker  on 
account  of  the  red  ring.  The  eggs  are  always  glued  to  the  apple  or 
leaf  and  one  often  finds  shells  which  remain  for  some  time  after  the 
larva  has  hatched.  The  reflection  of  light  from  the  egg  is  of  the 
greatest  aid  in  finding  them,  and  they  have  often  been  described  as 
reflecting  the  light  like  "trout  scales/'     (See  PI.  III.) 

PLACES    WHERE    LAID. 

Having  never  seen  the  egg.  the  early  writers  were  forced  to  guess 
as  to  where  it  was  laid.  They  stated  that  the  eggs  were  laid  either  in 
the  stem  end  or  in  or  about  the  calyx  end  of  the  apple.  These  views 
were  held  because  of  the  position  of  the  entrance  holes  of  the  larva3. 
These  ideas  were  published  again  and  again  for  over  a  century,  and 
American  writers  copied  them  until  about  1897,  when,  by  a  series  of 
observations,  it  was  proved  that  they  were  incorrect.  In  1889  Koebele 
and  Weir  stated  that  the  eggs  are  laid  at  any  point  upon  the  apple 
and  are  "  as  a  rule  laid  elsewhere  than  within  the  calyx."  Washburn 
in  189*2  found  that  the  eggs  were  "placed  on  both  sides  and  the  top 
of  the  fruit."  In  the  spring  of  1896  Slingerland  found  that  in  con- 
finement the  moths  laid  eggs  on  the  sides  of  the  cages,  on  leaves,  and 
on  bark.  Card  in  1897  found  that  the  egg>  were  laid  almost  exclu- 
sively upon  the  upper  surface  of  the  leaves,  and  in  1897  only  2  eggs 
were  observed  in  the  field.  In  a  recent  letter  Professor  Cordlev 
states  that  out  of  15  eggs  laid  in  confinement  the  greater  number  were 


2C> 

;i  the  fruit,  and  that  he  has  never  seen  an  egg  of  the  first  generation 
upon  t  he  fruit  in  the  field. 

The  apparent  contradictions  of  these  observations  may  be  accounted 
for  by  the  fact  that  they  were  made  upon  the  eggs  of  different  gener- 
ations of  the  insect.  The  writer  has  found  that  in  Idaho  but  few  of 
the  eggs  of  the  first  generation  arc  laid  upon  the  fruit.  In  one  limb 
cage  a  moth  laid  21  eggs,  only  one  of  which  was  upon  the  fruit;  and 
in  another  cap'  -I  eggs  were  laid  and  only  '2  were  upon  the  fruit. 
Very  few  eggs  of  this  generation  were  observed  to  have  been  laid 
upon  the  fruit  in  the  field.  Prof essor Cordley  suggests  that  the  moth 
does  not  lay  eggs  upon  the  young  fruit  on  account  of  the  pubescence, 
which  is  afterwards  lost.  This  is  most  probably  the  cause.  In  the 
tield  one  can  often  find  fruit,  surrounded  by  leaves,  upon  which  there 
are  no  egg*,  while  several  may  he  found  upon  the  upper  surface  of 
the  leaves. 

A  good  percentage  of  the  eggs  of  the  second  generation  are  laid 
upon  the  fruit  in  the  tield.  When  the  fruit  is  scarce  a  larger  number  is 
found  upon  the  leaves.  The  average  of  several  rough  countings  in  the 
tield  gave  an  average  of  about  50  percent  laid  upon  the  fruit.  Breed- 
ing records  show  that  out  of  175  eggs  of  this  generation  in  limb  cages 
on  inclosed  blanches  and  fruit  there  were  71  eggs  upon  the  leaves, 
(.K>  upon  the  fruit,  and  i>  upon  the  twigs.  Very  few  eggs  are  laid  upon 
the  underside  of  the  leaves,  and  it  seems  that  the  moth  much  prefers 
a  smooth  surface  upon  which  to  oviposit. 

We  may  therefore  conclude  that  the  eggs  of  the  first  generation  are 
for  the  most  part  laid  upon  the  leaves,  while  the  majority  of  those  of 
the  second  brood  may  be  found  upon  the  fruit. 

WHEN    THE    EGGS    ARE    LAID. 

Various  writers  have  stated  that  the  eggs  were  laid  at  night. 
Cooley  records  that  he  observed  a  moth  depositing  eggs  at  about  sun- 
set. The  writer's  observations  show  that  the  oviposition  for  the  most 
part  i-  accomplished  in  the  late  afternoon  or  early  evening,  while  a 
single  observation  shows  an  v^o;  to  have  been  laid  sometime  between 
'.»  and   L2  o'clock  in  the  morning. 

THE    MMI'.KK    OF    BOGS    LAID    \'A    <>\K    FEMALE. 

There  is  probably  less  definite  data  on  this  point  than  on  any  other 
in  the  life  history  of  the  insect.  Many  guesses  have  been  ventured  as 
to  the  number  of  eggs  that  one  female  will  lay,  varying  from  12  to 
:;»•<»  and  over.     LeBaron  found  from   t<>  to  60  eggs,  with  an  average 

of  50,  in  \  ;iiiou-  stages  <>f  development,  in  the  ovaries  of  the  fem.de  at 

the  time  of  emergence.     He  adds  that   if  all  the  undeveloped  eggs 
came  to  maturity   this  number  must   be  increased.     Matthew   Cooke 

-aid  that  he  had  :i  rial  in  his  possession  in  which  a  codling  moth  laid  85 


27 

eggs.  The  writer  was  unable  to  secure  eggs  in  this  way.  In  only 
two  instances  has  the  writer  made  definite  observations  on  the  number 

of  eggs  laid  by  a  single  female  moth.  Two  pair--  of  moth-  were 
secured  in  copula  and  placed  in  separate  limb  cages.  In  one  cage  21 
eggs  were  found,  but  as  the  moth  escaped  the  observation  was  incon- 
clusive. In  the  other  cage  25  eggs  were  laid,  but  a  spider  put  an  end 
to  the  experiment  before  a  definite  conclusion  was  reached.  In  view 
of  these  incomplete  observations  the  writer  can  only  venture  an 
opinion  that  the  maximum  number  of  eggs  laid  by  one  moth  is  about 
50,  with  the  average  between  30  and  4< ».  which  is  comparable  to  defi- 
nite records  of  other  insects  of  this  family. 

THE    EGO-LATINO    PERIOD. 

Tpon  dissection  of  the  ovaries  of  the  female  of  the  codling  moth 
the  eggs  are  found  in  various  stages  of  development.  It  is  also  noted 
that  eggs  are  laid  when  they  are  in  different  stages  of  maturity. 
From  these  facts  we  may  conclude  that  the  egg-laying  period  extends 
over  some  time.  Various  authors  have  given  the  length  of  time  from 
the  emero-ence  of  the  moth  to  the  beginning  of  the  laying  of  the  eo-o-s 
as  from  4s  hours  to  6  or  8  day-.  Professor  Gillette  gives  the  time  as 
about  5  days.  The  various  records  of  writers  show  that  this  time 
varies  from  2  to  7  days,  with  an  average  of  from  4  to  5  day-. 

DURATION    OF    EGG    STAGE. 

In  1746  Roesel  stated  that  the  egg  hatched  in  8  days.  Recent  authors 
give  the  length  of  the  stage  as  follows:  LeBaron.  one  week:  Wash- 
burn. 5  to  10  days:  Riley.  4  to  10  days;  Slingerland.  one  week:  Card. 
S  to  lo  days:  and  Professor  Gillette.  6  to  8  days  in  his  laboratory, 
with  a  known  temperature,  and  in  the  orchard  one  day  longer.  Cooley 
records  12  days  as  the  length  of  the  stage  of  one  egg. 

The  results  of  observations  upon  164  eggs  and  observations  of  Pro- 
fessor Cordley  are  given  in  Table  I.  with  the  total  and  average  effect- 
ive temperature  to  which  the  eggs  were  subjected. 

Table  I. — Duration  of  egg  .<ta<ii  of  codling  moth. 


May 


Aug.  11 
Aug.  12 

Aug.  16 
Aug.  26 


1902. 


Date 

Number 

Period  of 
incuba- 

Total  ef- 
fective 

Average 
effective 

hatched. 

hatched. 

tempera- 

tempera- 

ture. 

ture. 

1902. 

F. 

;  F 

June  11 

1 

12 

228 

ly 

June  12 

3 

13 

_ 

ly 

June  13 

17 

14 

347 

24.7 

Aug.  21 

3 

9 

0 

12 

22 

6 

9 

217 

21 

Sept.     5 

u 

11 

247 

22 

Sept.    6 

3 

12 

23 

28 


Table  1.     Duration  ofeggstant  of  codling  moth — Continued. 


Date  laid. 


1902. 


Aug.  27 
Aug.  28 


Do. 

Aim.  29 


Mnv 


Number 

Date 

Number 

Period  of 
Incuba- 

Total  ef- 
fective 

Average 
effective 

laid. 

hatched. 

hatched. 

tempera- 

tempera- 

ture. 

ture. 

1902. 

D'n/s. 

o  p 

o  p 

27 

Sept.    •"> 

- 

9 

278 

30 

Sept.     6 

n 

10 

807 

27 

Sept.    8 

2 

12 

360 

27 

61 

Sept.    8 

9 

11 

269 

24 

Sept.    '.' 

I 

12 

296 

24 

Sept.    12 

32 

i:» 

364 

24 

Sept.  15 

2 

18 

128 

24 

n 

Sept.     9 

1 

12 

216 

18 

Sept.     6 

11 

9 

269 

29 

Sept.   15 

1 

18 

24 

40 

Sept.     8 

3 

10 

25 1 

26 

Sept.     9 

6 

11 

286 

25 

Sept  12 

3 

11 

349 

24 

187 

164 

243 



8 

June     1 

J  I 

298 

12 

15 

May   12 

6 

286 

17 

The  results  under  normal  orchard  temperature  give  the  length  of 
the  stage  from  9  to  L8  days,  with  a  weighted  average  of  11  days.  This 
average  is  longer  than  has  been  given  by  other  authors,  which  may 
be  accounted  for  by  the  fact  that  it  is  the  usual  custom  to  keep  the 
eggs  in  laboratories  rather  than  under  normal  orchard  conditions,  and 
that  the  times  of  the  laying  of  the  eggs  were  estimated. 

HATCHING    OF   THE    EGG. 

Recent  authors  are  quite  well  agreed  as  to  how  the  larva  breaks  or 
eats  its  way  out  of  the  shell.  Professor  Slingerland  was  most  proba- 
bly the  first  to  observe  this  operation.  He  states  that  the  larva  came 
out  of  the  egg  near  the  edge  at  one  end  through  an  irregular  crack  in 
the  shell.  (PI.  Ill,  es.)  The  writer  has  never  observed  this  emer- 
gence, but  upon  examining  many  egg  shells  an  irregular  crack  was 
always  found  which  was  almost  always  at  one  end  of  the  shell. 

CHANGES    DURING    [NCUBATION. 

When  laid  the  egg  is  of  a  translucent  pearly  color,  often  with  a 
yellowish  tinge.  Observations  upon  88  egg*  show  that  from  '2  to  5 
days  with  a  weighted  average  of  8  days  after  being  laid  a  red  ring 
makes  its  appearance.  This  ring  appears  gradually  at  first  whitish, 
then  yellowish,  and  later  quite  a  brilliant  red.  By  observations  upon 
.m;  egg>  it  was  found  that  in  from  V  to  1<>  days,  with  a  weighted  aver- 
age of  8.  1-  days  after  being  laid,  the  egg  loses  the  ring  and  in  its  place 
the  larva  can  be  seen,  the  "black  spot/'  which  consists  of  the  head 
and  cervical  shield,  being  the  most  conspicuous  part. 

Professor  Gillette  states  that  his  assistant,  Mr.  E.  P.  Taylor,  found 
tin-  n'(\  ring  t<>  appear  in  from  2  to  ."»  days  after   laying  and  the  black 


29 


spot   appeared   2   to   3   days   later.      This   shorter 
accounted  for  by  the  fact  that  these  eggs  were  kept  at  a 
perature  than  normal. 


iverage   may  be 


higher  teni- 


METHODS    OF    OBTAINING    EGGS. 

There  are  two  ways  of  obtaining  eggs  for  study.  The  first  is  to 
collect  them  in  the  field  and  place  them  under  observation  in  cages. 
There  is  a  serious  objection  to  this  method,  as  there  is  no  way  of 
knowing  the  age  of  the  eggs.  The  second  method,  that  of  confining 
larvae  and  pupae  and  allowing  the  moths  to  emerge,  is  far  more  satis- 
factory. If  these  moths  are  placed  in  a  cage  over  a  limb  of  a  tree, 
one  will  find  eggs  in  abundance  in  a  day  or  two.  One  is  sometimes 
fortunate  enough  to  find  moths  in  copula,  and  in  that  event  the}T 
should  be  placed  in  a  separate  cage.  By  determination  of  sex  of  the 
various  moths  much  more  valuable  data  can  be  secured.  Care  must 
be  taken  that  too  many  eggs  are  not  laid  in  one  cage,  as  in  that  event 
it  is  difficult  to  keep  accurate  notes.   ■ 

These  limb  cages  are  bags  made  of  mosquito  netting  of  finer  mesh 
than  the  ordinary  netting.  By  this  method  the  leaves  and  fruit  are 
always  fresh  and  the  conditions  are  exactlv  the  same  as  in  the  orchard. 


INFLUENCE    OF    TEMPERATURE   UPON    THE    LENGTH    OF    THE    EGG    STAGE. 

It  has  often  been  stated  that  a  higher  temperature  caused  the  eggs 
to  hatch  in  a  shorter  time,  but  only  a  few  definite  observations  have 
been  recorded.  The  temperature  used  in  these  calculations  is  the 
effective  temperature,  which  is  obtained  hy  subtracting  43^  from  the 
mean  daily  temperature  as  recorded  by  the  United  States  Weather 
Bureau  station  at  Boise,  Idaho. 

Professor  Gillette  gives  6i  days  as  the  length  of  this  stage  at  a  tem- 
perature of  from  68°  to  70°  F.  and  6  days  as  the  time  in  a  greenhouse 
where  the  temperature  was  110°  F.  at  midday.  In  Table  I  the  total 
and  average  effective  temperature  is  given  from  the  time  the  eggs 
were  laid  until  the}T  were  hatched.  These  data  are  arranged  accord- 
ing to  the  temperature  in  Table  II. 

Table  II. — Effective  temperature  and  period  of  incubation. 


Average 

Total 

Average 

Total 

Average 

Total 

effective 

effective 

Length 

effective 

effective 

Length 

effective 

effective 

Length 

temper- 

temper- 

of stage. 

temper- 

temper- 

of stage. 

temper- 

temper- 

of stage. 

ature. 

ature. 

ature. 

ature. 

ature. 

ature. 

°F. 

°  F. 

Days. 

°  F. 

o  p 

Days. 

o  p 

o  p 

Dai/s. 

12 

298 

'21 

24. 

217 

9 

25 

254 

10 

18 

216 

12 

24 

269 

11 

25 

280 

11 

19 

228 

12 

24 

295 

12 

27 

307 

10 

19 

253 

13 

24 

349 

14 

27 

366 

12 

22 

247 

11 

24 

364 

15 

29 

269 

9 

22 

266 

12 

24 

428 

18 

30 

278 

9 

23 

206 

9 

24 

428 

18 

17 

2S5 

5 

23 

276 

12 

25 

217 

14 

Average  total  effective  temperature,  302°  F. 


30 

This  table  i-  not  complete,  in  that  not  sufficient  observations  were 
made  at  lower  and  higher  temperatures;  and  it  is  dangerous  to  make 
anv  extended  conclusions  therefrom.     A  study  of  the  table  shows: 

First.  Under  a  low  temperature  the  Length  of  this  stage  is  longer 
than  at  high  temperatures. 

Second.  The  total  temperature  varies  from  206  to  428  F.,  and  the 
average  is  302  ;  and  in  general  eggs  have  to  be  subjected  to  this 
amount  of  heal  before  they  hatch,  whether  it  be  for  a  longer  or  a  shorter 
period  of  time. 

Third.  The  eggs  are  not  at  the  same  state  of  maturity  at  the  time  of 
oviposition,  as  at  24   we  have  from  9  to  18  days  as  the  length  of  stage. 

Fourth.  Under  normal  field  conditions  a  small  difference  in  temper- 
ature causes  but  little  change  in  the  Length  of  the  stage. 

MORTALITY  AMONG    THE    EGOS. 

Various  observers,  among  them  Washburn,  Goethe,  Card,  Slinger- 
Land,  and  Cordley,  have  found  that  many  eggs  of  this  insect  did  not 
hatch.  There  is  little  doubt  that  at  least  one  of  these  writers  mistook 
eggs  from  which  the  larva1  had  hatched  for  dead  eggs.  The  writer 
has  noted  that  many  eggs  became  hard  and  dry,  while  in  others  the 
contents  changed  to  a  dark  brown  color.  These  changes  may  have 
been  caused  by  infertility,  parasites,  or  the  excessively  hot  sun.  The 
mortality  as  shown  by  our  breeding-cage  records  is  by  no  means  so 
great  as  the  writer  had  supposed.  The  eggs,  however,  were  more  or 
less  protected. 

THE  LARVAL  STAGE. 

( Jonsidering  the  codling  moth  in  its  economic  relations,  it  may  be  said 
that  the  Larval  is  the  most  important  stage  of  the  insect.  Not  only  is 
it  distributed,  and  does  all  of  its  damage  in  this  stage,  but  it  is  more 
amenable  to  remedial  measures. 

At  the  time  of  hatching  the  young  larva  is  from  one-twentieth  to 
one-sixteenth  of  an  inch  in  length,  of  a  semi-transparent  whitish  or 
yellowish  color,  with  Large,  shiny,  black  head,  and  dark  cervical  and 
anal  shields.  The  body  shows  regularly  arranged  spots  with  short 
hair-  or  seta1. 

If  hatched  upon  the  apple  tin1  young  Larva  seeks  a  place  to  enter, 
which  is  in  general  some  irregularity  upon  the  apple  or  at  the  calyx. 
Slingerland,  Card,  and  Cordley  have  made  many  excellent  observa- 
tion- upon  the  place  of  entrance.     When  hatched  upon  the  leaves  they 

ma\  not  find  an  apple  for  some  time,  and  subsist  by  eating  small  por- 
tion-of  the  Leaves.  In  confinement  this  often  occurs,  but  it  has  never 
been  determined  accurately  how  often  it  takes  place  in  the  tield.  The 
writer  ha-  time  and  again  npted  these  spots  on  the  Leaves  in  the  field, 

and  has  noted  also  that  larva1  hatched  on  leave- wonld  have  to  Efofrom 


31 

10  to  iJO  feet  before  they  could  rind  an  apple:  Curd  notes  that  compara- 
tively few  eat  of  the  leaves  in  the  open,  but  from  such  observations 
as  we  have  the  writer  is  strongly  of  the  opinion  that  it  is  quite  a  gen- 
eral habit. 

DESCRIPTION    OF    FULL-GROWN    LARVA. 

When  fall  grown  the  larvae  are  about  three-quarters  of  an  inch  in 
length,  and  their  heads  measure  from  1.51  to  1.76  mm.  across  the 
broadest  portion.  The  majority  are  of  a  pinkish  or  flesh  color,  which 
is  much  lighter  or  absent  on  the  under  side.  It  was  thought  for  a 
long  time  that  the  pink  color  was  due  to  the  larva  having  fed  on  some 
particular  varieties  of  apple:  but  the  white  and  pink  larvae  have  often 
been  found  feeding  on  fruit  from  the  same  tree.  The  head  is  brown 
in  color,  with  darker  markings,  while  the  cervical  and  anal  shields  are 
much  lighter.  The  spots  in  which  the  minute  short  hairs  are  situated 
are  but  little  darker  than  the  body  wall,  but  can  be  easily  distinguished 
with  a  hand  lens.  The  mandibles  are  the  most  noticeable  feature  of 
the  mouth  parts.  Beneath  the  under  lip  is  the  spinneret,  from  which 
the  silken  thread  is  drawn.  The  larva  has  eight  pairs  of  legs.  The 
first  three  pairs,  or  true  legs,  are  situated  on  the  thorax,  and  are  three 
jointed.  Later  these  form  the  legs  of  the  adult  insect.  The  five  pairs 
of  fleshy  abdominal  legs,  or  prolegs.  disappear  in  the  pupal  stage  of 
the  insect.  The  first  four  pairs  of  legs  are  armed  with  circles  of 
hooks,  while  the  hooks  on  the  two  pairs  at  the  end  of  the  body  are 
arranged  in  a  semicircle.  The  spiracles  or  breathing  apertures  of  the 
larva  are  arranged  on  either  side  on  separate  segments  of  the  body. 
(PLY,  fig.  1.) 

ENTERING    THE    FRUIT. 

The  usual  place  of  entrance  of  the  first  generation  is  by  way  of  the 
calyx.  The  larva1  either  squeeze  their  way  into  the  calyx  between 
the  lobes  or  tunnel  into  the  cavity  at  the  base  of  the  lobes.  A  scar, 
the  stem,  or  a  place  where  fruits  touch  is  often  selected  as  the  place 
of  entrance.  In  1900  the  writer  observed  an  egg  shell  with  a  larval 
entrance  hole  at  the  edge  and  partly  under  the  shell.  In  view  of  later 
observations  it  is  more  probable  that  some  larva  crawling  around 
found  this  obstruction  and  entered,  rather  than  that  the  larva  entered 
the  fruit  directly  from  the  shell. 

The  second  generation  for  the  most  part  enter  on  the  sides  of  the 
fruit.  The  larva  crawls  rapidly  about  the  apple,  seeking  a  place  for 
entrance.  A  scar  or  roughness  is  a  favorite  place,  as  the  jaws  slip  on 
the  smooth  skin.  In  its  wanderings  the  larva  spins  a  silken  thread  and 
finally  makes  a  web  over  the  surface  of  the  apple.  With  this  as  a 
foothold  it  is  able  to  make  some  impression  upon  the  skin,  which  is 
bitten  out  in  chips  and  dropped  into  the  web.  Later,  when  it  is  partly 
covered,  the  larva  backs  out  of  the  burrow  and  brings  pieces  out  with 


32 

it.  This  is  repeated  until  it  is  entirely  within  the  burrow,  when  it 
turns  around  and  spine  a  silken  net  over  the  hole,  in  which  may  be 
incorporated  -«  \  «■  i  u  I  pieces  of  the  fruit.     (PI.  IV.  fig,  L.) 

Slingerland,  Card,  and  Cordley  have  also  noted  these  larvae  enter, 
and  the  observations  made  bj  the  writer  agree  entirely  with  theirs. 
One  of  the  essentia]  points  noted  is  that  while  entering  none  of  the 
larvae  seem  to  cat  an\  of  the  fruit  until  well  within  the  burrow,  and 
it  mosi  probably  gets  some  of  the  poison  applied  in  spraying  when 
it  attempts  t<>  pierce  the  skin.  The  writer  has  observed  numerous 
larger  Ian  ro,  and  is  quite  positive  that  they  do  not  cat  any  of  the  fruit 
while  they  arc  entering. 

PLACES   OF    ENTRANCE. 

The  places  of  entrance  of  the  successive  broods  are  quite  different. 
Various  authors  have  stated  that  from  60  to  80  per  cent  of  the  larvae 
of  the  first  generation  enter  the  fruit  by  the  calyx.  In  L901  several 
countings  gave  an  average  of  83  per  cent,  with  a  minimum  of  7'.»  per 
cent.  In  L902  much  more  extensive  countings  gave  a  maximum  of 
'.•:;  ])(■!•  cent,  a  minimum  of  50  per  eent.  and  an  average  of  81  per  cent. 
(Table  III.)  Less  than  one-half  of  1  per  eent  enter  by  the  stem  end, 
while  the  larger  remaining  percentage  enter  the  side,  especially  where 
fruits  touch 

The  majority  of  the  second  generation  enter  the  side  of  the  fruit. 
A  few  counts  in  L901  showed  that  the  greater  part  of  the  larvae  entered 
the  side,  and  a  few  cases  showed  that  from  90  to  LOO  percent  had 
entered  at  that  place.  Countings  on  1.47*  apples  in  September,  1902, 
on  both  sprayed  and  unsprayed  trees,  are  given  in  Table  III. 

Table  [II. — Percentagt  of  firsl  generation  entering  calyx. 

SPRAYED  Ti:i 


<  orchard. 

Variety. 

Date. 

-trill. 

Calyx. 

TotaL 

Per  <•.  nt 
iu  calj  x. 

IftcPheroon .                     



teler 

Jonathan 

H«n  l»a\  i- 

do 

July  18 

.lulv  22 
July   19 

0 
0 
0 

•J 
■1 

•J 
8 

16 

Total  ... 

0 

12 

88 

69 

B2.  6 

• 

ITNSPR  \YKI»    I  i;i  ES 


.1    |>  <,n.\  .                                  

.lulv    17 
.lulv    19 
July  21 

.lulv   25 
.lulv   22 
.lulv  :;i 

•J 
i' 

- 

J 

7 

21 

■1 

18 

100 
LOO 

257 
15 

Da                              

Do 

l»r  Col 

by 

91.8 

•_> 

108 

VIA 

Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  IV. 


I 


Fig.  1.— Entrance  Holes  of  Larv/£  of  the  Second  Generation. 


Fig.  2.— View  in  Orchard  of  Hon.  Edgar  Wilson.  Showing  Location  of  Apple 
House  in  Relation  to  Orchard. 


Fig.  3.— Another  View  in  Orchard  of  Hon.  Edgar  Wilson,  Showing  Location 
of  Apple  House  with  Reference  to  the  Railroad. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  V. 


Fig.  1.— Codling  Moth  Larva  (Enlarged  About  3  Times) 


[fl 


Fig.  2.— The  Wormhole  or  Exit  Hole  of  the  Apple  ^Enlarged). 


Fig.  3.— A  Wormy  Apple,  Showing  the  Familiar  Mass  of  Brown  Particles  Thrown 
Out  at  the  Blossom  End  by  the  Young  Larwe  (from  SlingerlandL 


33 


Places  of  entrana  of  the  second  <j<  neration. 

DWSPRAYED  TREE-. 


Stem. 

Bide. 

Calyx. 

T<»tal. 

Per  cent 
calyx. 

4 

(V, 

57 

127 

44.4 

5 

74 

a 

110 

28.1 

12 

104 

76 

192 

39.  o 

4 

" 

41 

142 

28.8 

1 

. 

12 

33 

36.3 

1 

58 

14 

73 

19.1 

27 

419 

231 

077 

a26.1 

SPRAYED  TREES. 


, 

56 

28 

85 

32 

11 

204 

21 

236 

8.8 

0 

37 

36 

73 

49.3 

0 

41 

14 

55 

•25.4 

0 

32 

9 

41 

21.9 

0 

50 

34 

-4 

40.4 

0 

19 

18 

*     37 

48.7 

0 

50 

21 

71 

29.5 

1 

11 

12 

24 

50 

0 

32 

16 

4^ 

33.  5 

0 

22 

. 

29 

24.1 

0 

9 

9 

H 

50 

13 

563 

225 

801 

a  28 

a  Average. 

The  tables  of  the  places  of  entrance  of  the  first  generation  on 
sprayed  trees  show  some  interesting  facts,  and  it  is  to  be  deplored 
that  the  records  are  not  more  extensive. 

No  definite  data  was  secured  in  regard  to  what  percentage  of  the 
larva?  enter  the  sides  where  fruits  are  touching.  In  badly  infested 
orchards  it  is  almost  impossible  to  find  such  fruits  into  which  a  larva 
has  not  entered.  It  would  be  safe  to  estimate  that  fully  50  per  cent, 
if  not  more,  of  the  larva?  entering  at  the  sides  eater  where  the  fruits 

touch. 

Immediately  after  entering  the  calyx  cavity  the  larva  take-  its 
first  meal.  We  have  a  lack  of  data  as  to  exactly  what  is  eaten,  but 
most  probably  the  larva  acts  as  it  does  wherbthe  side  is  entered.  After 
spinning  the  web  over  the  hole  the  larva,  when  it  enters  the  side,  eats 
out  a  cavity  under  the  skin  and  throws  out  but  little  castings.  This 
mine  is  eaten  outward  from  the  point  of  entrance,  and  in  from  8  to  5 
days  the  larva  begins  its  tunnel  toward  the  center  of  the  fruit,  reach- 
ing that  point  when  about  one-qua.rter  grown  and  about  a  week  old. 

While  at  the  surface,  or  while  tunneling  toward  the  center  of  the 
apple,  the  larva  pushes  its  excrement  and  frass  through  the  entrance 
hole.  Later  the  entrance  hole,  especially  at  the  calyx,  is  enlarged, 
and  a  considerable  amount  of  frass  is  thrown  out.  which  characterizes 
the  infested  fruit  (PL  V.  fig.  3).  When  a  considerable  cavity  has  been 
made  in  the  interior  of  the  apple  the  excrement  is  bound  together  with 
silk.  Upon  reaching  the  central  portion  of  the  fruit  the  larva  eats 
6514— No.  41—03 3 


34 

out  an  irregular  cavil y  about  t ho  core,  and  seems  especially  partial 
to  the  seeds. 

The  insects  pass  through  five  larval  stages,  and  increase  in  size  by 
shedding  their  skins  four  times  to  allow  for  growth.  The  width  of 
the  head  of  the  larva  in  these  different  stages  averages  as  follows: 
First  stage,  0.3s  mm.;  second  stage,  0.55  mm.;  third  stage,  0.78  mm.; 
fourth  stage,  1.12  mm.;  fifth  stage,  1.6  mm.  When  in  the  latter  part 
of  the  first  stage  and  the  second  part  of  the  third  stao*e  the  larva'  are 
whitish  iu  color,  but  with  the  cervical  and  anal  shields  black,  and 
with  blackish  spots  around  the  seta?.  In  the  later  stages  the  shields 
become  brown,  and  the  spots  around  the  hairs  are  usually  indistinct, 
especially  in  the  pinkish  larva?. 

TIME    SPENT    IN    THE    FRUIT. 

Very   few  definite  observations  have  been  made  in  regard  to  the 

time  the  larva  spends  inside  the  fruit.  Le  Baron  gave  the  time  as 
four  week-:  Riley,  25  to  30  days;  Slingerland,  20to30  days;  Card,  1<» 
to  1  I  days;  and  Cordley,  L6  to  24-  days.  From  the  nature  of  the  case 
it  is  most  difficult  to  get  exact  data  on  this  point,  as  there  are  many 
accidents  which  may  prove  fatal  to  the  experiment.  On  only  5  larvae 
was  the  writer  able  to  obtain  results  definite  enough  to  use  with  any 
degree  of  confidence.  One  of  these  lar\;e  remained  in  the  apple  14 
days,  two  IS  days,  one  21  days,  and  another  26  days.  Professor  Gil- 
lette kindly  furnishes  some  unpublished  data  on  this  point,  in  which 
he  finds  larva' to  have  stayed  in  the  fruits  12,  is.  20,  and  24  days, 
respectively,  with  an  average  of  L9  days.  The  average  of  all  these 
observations  is  about  20  days. 

PREPARATIONS    FOR    LEAVING    THE    FRUIT. 

When  about  full  grown  the  Larva  makes  a  passageway  to  the  out- 
side of  the  fruit.  This  18  usually  made  toward  the  side  of  the  apple, 
in  a  different  direction  from  that  from  the  entrance  hole.  Rarely 
doe-  the  exit  passage  follow  along  or  consist  of  the  enlarged  entrance 
passage.  Before  the  larva  has  passed  outside  the  outer  portion  of  the 
passage  is  filled  with  a  block  of  frass(Pl.  V.  fig.  2,  a),  or  a  cap  of  silk  is 
spun  over  the  hole. 

LEAVING    THE    FRUIT. 

When  ready  to  leave  the  fruit  the  larva  pushes  out  this  block  or 
tear-  away  the  cap  of  silk,  crawls  out  on  the  surface  of  the  apple,  and 
immediately  Seeks  a  place  in  which  to  spin  a  cocoon.      (PI.  V,  fig.  2,  t>.) 

If  the  apple  is  upon  the  tree  the  larva*  will,  in  by  far  the  greater  num- 
ber of  cases,  crawl  from  the  apple  to  the  twig,  from  there  to  the 
branch,  and  thence  down  upon  the  trunk  of  the  tree.  Another  method, 
which  is  comparatively  rare,  18  that  in  which  the  larva  lets  itself  down 


35 

to  the  ground  by  moans  of  a  silken  thread.  This  may  be  on  account 
of  the  fact  that  the  larva1  sometimes  drop  accidentally  and  use  the 
silken  thread  to  support  themselves.  It  is  not  uncommon  to  find  these 
threads  extending  through  the  branches  of  trees  which  are  badly 
infested  with  the  codling-  moth. 

Professor  Gillette  finds  that  85  per  cent  of  the  Larvae  enter  the  bands 
during-  the  night,  and  the  remaining  15  per  cent  during  the  day.  in 
Ausrust.  Observations  of  the  writer  show  that  in  the  summer  the 
larger  percentage  enter  the  bands  from  6  p.  m.  to  about  11  p.  m.,  at 
Boise,  Idaho.  After  11  p.  m.  it  is  usually  so  cool  that  there  is  but 
little  activity.  In  September  the  conditions  as  given  b}T  Gillette  are 
about  reversed.  The  nights  arc  cold,  and  the  larvae  arc  active  only 
during  the  warmer  Darts  of  the  day,  at  which  times  they  enter  the 
bands. 

If  the  apple  has  fallen  to  tne  ground  the  larva  simply  crawls  into  a 
convenient  place  and  spins  its  cocoon.  After  leaving  the  fruit  the 
larva  is  unprotected,  and  does  not  consume  much  time  in  finding  a 
place  to  start  its  cocoon. 

PLACES   OF   SPINNING    COCOONS. 

In  orchards  the  cocoons  are  normally  found  in  cracks  or  holes  in 
branches  or  trunks  of  the  trees,  under  scales  of  rough  bark,  and  in 
the  rough  bark  on  the  main  branches  of  the  trees.  When  the  trunk 
of  a  tree  is  smooth  the  cocoons  are  often  found  under  bits  of  bark 
and  in  the  earth  about  the  foot  of  the  trees.  Cocoons  are  found  under 
anything  on  the  tree  or  leaning  against  it,  as  bands  placed  around  the 
trunk,  rags  tied  around  the  limbs,  or  boards  and  sticks  leaning  against 
the  tree.  When  much  fruit  h  s  fallen  the  larva'  seem  to  have  a  greater 
range  in  spinning  cocoons,  often  placing  them  among  clods  of  earth, 
beneath  paper  or  any  other  rubbish  on  the  ground,  in  the  cracks  and 
rough  bark  of  adjacent  trees,  in  piles  of  wood  or  lumber,  in  fence 
posts,  and  under  the  pickets  of  fences.  In  piles  of  fruit  in  the  orchards 
the  cocoons  are  normally  found  placed  among  the  apples;  in  orchards 
where  the  trunks  and  branches  of  the  trees  are  smooth,  the  cocoons 
are  often  found  in  the  cracks  of  the  earth  about  the  foot  of  the  trees, 
and  when  fruit  is  lying  on  the  ground  they  have  been  found  among 
the  clods  of  earth  by  Cordley  and  McPherson.  Cordlev  published  a 
photograph  showing  a  cocoon  on  a  clod  of  earth.  In  the  writer's 
experience  two  cases  have  been  found  in  which  a  cocoon  was  spun 
inside  of  wormy  fruit.  It  was  impossible  to  tell  whether  or  not  the 
larvae  which  had  spun  these  cocoons  were  those  which  had  done  the 
injury  to  the  fruit.  In  packing  houses  it  is  quite  common  to  find  the 
larvae  in  cracks  of  the  floor,  walls,  and  roof,  in  piles  of  lumber  or 
boxes,  and  in  the  angles  and  cracks  of  boxes  or  barrels  used  for  han- 
dling tne  fruit.     The  larva  usually   gnaws  out  a  cavity   in   which  to 


36 

spin  its  cocoon.  These  cavities  are  often  found  in  the  interior  of 
rotten  trees,  stumps,  and  fence  posts,  with  passages  excavated  into 
these  rotten  pieces  of  wood  from  2  to  4  inches.  In  the  spring  cocoons 
can  l>e  found  only  in  the  more  secure  places,  those  spun  in  more 
exposed  places  having  been  eaten  by  their  enemies.     (See  PI.  VIII.) 

DESCRIPTION    ()F   Till-:   COCOON. 
The  cocoon  is  composed  of  silk,  which  Is  the  product  of   the  pair  of 

silk  glands  common  in  many  orders  of  insects.  These  glands  are  sit- 
uated on  either  side  of  the  alimentary  canal,  and  consist  of  three  parts, 
each  of  which  bas  a  separate  function.  The  cephalic  portions  unite  to 
forma  single  tube  in  the  head  of  the  insect,  which  extends  to  the 
externa]  opening  orspinneret.  The  spinneret  is  a  chitinous  projection 
on  the  under  side  of  the  labium  or  lower  lip.  Throughout  its  life  the 
larva  makes  use  of  this  silk  in  various  ways. 

When  a  suitable  place  has  been  selected  for  the  spinning  of  a  cocoon 
the  larva  begins  to  weave  about  itself  this  single  thread  of  silk.  The 
exterior  outline  of  the  cocoon  conforms  to  that  of  the  cavity  or  crack 
in  which  it  is  placed.  While  spinning  the  larva  is  bent  upon  it -elf 
and  decreases  considerably  in  size.  When  the  cocoon  is  completed, 
which  takes  usually  about  one  day.  the  larva  straightens  out  and  con- 
tracts in  length.  While  the  exterior  of  the  cocoon  may  be  rough,  the 
interior  is  always  smooth  and  oval  in  shape.  At  completion  of  the 
spinning  of  the  cocoon  the  alimentary  canal,  silk  elands,  and  other 
organs  peculiar  to  the  larva  begin  to  disintegrate. 

In  from  1  to  1!>  days,  with  an  average  of  about  6  days,  the  larval 
skin  is  shed  and  the  insect  becomes  a  pupa.  The  east  larval  skin  can 
always  be  found  at  the  caudal  end  of  the  body,  shriveled  into  a  rounded 
mass. 

Various  authors  have  noted  that  when  the  cocoon  of  the  codling 
moth  is  torn  or  cut  open,  it  is  immediately  repaired  by  the  larva. 
Professor  Slingerland  states  that  the  damage  is  repaired  in  winter. 
He  ha-  also  had  a  larva  spin  two  or  three  complete  cocoons  after  hay- 
ing been  removed  very  early  in  the  spring  from  the  one  in  which  it 
had  hibernated.  The  writer  had  one  spin  two  new  cocoons  during 
the  summer.  Professor  Gillette  notes  that  in  Colorado  the  larva? 
leaving  the  cocoons  in  the  early  spring  leave  those  in  which  they  have 
hibernated  and  seek  other  places  in  which  to  spin  new  ones  and 
pupate.      He  reports    that  under  in    bands    placed   on    the  trees    in  the 

early  spring  •'»  larvae  which  were  spinning  new  cocoons  were  taken. 

Various  reasons  might  be  assigned  for  this  habit  of  the  insect.  It 
might  lie  that  the  cocoons  are  too  deep  in  the  wood  of  the  trunk  of 
the  tree  for  the  moth  to  emerge  without  materially  injuring  itself,  or 
it  may  be  thai  the  larva  on  becoming  active  in  the  spring  finds  itself 

in  a  \\<'t  place,  and.  for  either  of  these  or  some  other  reason,  migrates 
t<>  :i   bcllci-  place  and  spins  itself  a  new  cocoon. 


37 

One  of  Professor  Gillette's  correspondents  reports  that  he  tound  53 
larvae  under  295  bands  in  two  weeks.  Another  reports  307  larvae 
April  2  and  409  April  17  from  2,500  hands.  Gillette  thinks  that  the 
number  caught  under  these  bands  is  too  small  to  be  of  any  great 
value  as  a  remedial  measure. 

DURATION    OF    THE    STAGES    IX    THE    COCOOX. 

On  account  of  the  direct  influence  of  this  question  upon  the  system 
of  banding,  particular  care  was  taken  to  ascertain  the  duration  of  the 
cocoon  sta<?e,  and  especially  the  minimum  time.  The  older  writers 
gave  estimates  of  this  time  with  but  little  definite  data.  Riley  gave 
from  15  to  21  days:  Washburn,  3  weeks:  Slingerland,  2  to  3  weeks. 
and  Aldrich  about  1  week.  Professor  Gillette  gives  records  of  com- 
plete experiments  upon  this  point.  In  1900  observations  made  for 
him  upon  104  larvae  gave  a  minimum  of  1:2  days,  a  maximum  of  29 
days,  with  an  average  of  20  days.  Other  experiments  directed  by  the 
same  writer  in  1901  on  76  larvae  resulted  in  finding  the  minimum  to  be 
3  days:  maximum.  23  days,  and  average  16f  days.  In  1900  the 
writer  found  that  in  7  cages  the  shortest  time  varied  between  12  and 
15  days,  with  an  average  minimum  of  about  14  days.  In  1902  a  large 
series  of  breeding  experiments  were  carried  out.  the  results  of  which 
are  incorporated  in  the  following  table: 

Table  IV. — Duration  of  lift  oftfu  codling  moth  inside  the  cocoon. 


Date  <>f  entering  band. 


Number       Date 


of 


Miotic 


larva-,     emerged. 


Xurnber 
of  moths. 


Time, 


Total  Average 
effective  effective 
tempera-  tempera- 
ture, ture. 


June  29. 

July  14. 

July  22. 
July  29. 


July  31 , 


1902. 


Aug.   6. 


1902. 
July  19 
July  21 
July  22 
July  30 
July  31 
Aug.     1 

Aug.    .; 

Aug.  9 
Aug.  11 
Aug.  29 
Sept  l 
Sept.  5 
Sept.  9 
Aug.  9 
Aug.  11 
Aug.  12 
Aug.  13 
Aug.  15 
Aug.  16 
Aug.  18 
Aug.  19 
Aug.  20 
Aug.  21 
Aug.  22 
Aug.  25 
Sept.  9 
Aug.  18 
Aug.  19 
Aug.  20 

Aug.  23 

^Ug.  1^ 

Aug.  19 

Aug.  21 

Aug.  22 

Aug.  23 


Bays. 


°F. 


°F. 


2 

20 

433 

21 

2 

•  >•> 

505 

23 

2 

23 

.543 

24 

1 

If. 

494 

31 

4 

17 

528 

31 

0 

18 

566 

31 

1 

23 

722 

31 

•> 

18 

32 

: 

20 

645 

32 

l 

38 

1.115 

29 

<; 

41 

1.170 

29 

2 

45 

1,284 

29 

2 

49 

1.392 

28 

3 

11 

3H2 

33 

3 

13 

424 

33 

3 

14 

4.55 

32 

6 

15 

481 

32 

5 

17 

541 

32 

2 

1^ 

31 

5 

2ii 

600 

30 

. 

21 

615 

29 

1 

22 

633 

29 

2:: 

661 

29 

5 

24 

693 

29 

2 

27 

78 

29 

1 

42 

1.171 

28 

2 

1^ 

30 

1 

19 

550 

29 

1 

- 

553 

28 

1 

21 

581 

28 

3 

23 

641 

28 

1 

12 

209 

17 

1 

13 

224 

17 

3 

15 

270 

18 

4 

16 

- 

19 

3 

17 

330 

19 

88 


Table  IV.     Thiration  of  lif  ofthi  codling  moth  inside  the  cocoon—  Continued. 


■  ntering  band. 


Number       Date 


of 
larvae. 


moths 
emerged 


Aug.   6. 


Aug.  IS. 


Aug.  15. 
Aug.  20. 
Aug.  22. 


1902. 
Aug.  25 
Aug.  26 

Auk.  27 
Auk.  28 
Aug.  29 
Aug.  30 
Bept.    1 

do  ... 

Sept.    8 

....do... 
Bept.  12 

<]<> ... 

Sc|it.   17 


Nuiiil.tr 
6t  moths. 


Time. 


1>(II/S. 


Total 
tempera- 
ture. 


392 
125 
156 
185 
503 
519 

168 
(171 
604 
607 
547 
633 


Average 
tempera- 
ture. 


24 


The  number  of  larvae  used  was  17<»,  and  the  stage  varied  from  11  to 
49  days,  with  u  weighted  average  of  *2'2  days.  This  average  is  some- 
what longer  than  that  secured  by  other  observers,  and  may  be  partly 

accounted  for  by  the  lateness  of  the  season. 

The  principal  point  to  he  clearly  shown  is  the  Length  of  the  mini- 
mum stage,  which  these  experiments  show  to  he  not  less  than   1<>  to   1 1^ 

days. 

The  time  spent  in  the  cocoon  by  the  hibernating  larvae  varies  con- 
siderably, but  usually  lasts  about  eight  months.  If  the  larva*  are 
taken  inside  and  kept  where  the  temperature  is  higher,  moths  will 
sometimes  emerge  in  .January  or  February. 


IMI.ll.M  IB    OF   TEMPERATURE    DPON    THE    DURATION    OF   THE    STAGE. 

Various  authors  have  stated  at  various  times  that  this  stage  might 
be  considerably  lengthened  or  shortened  by  temperature.  Table  V 
shows  a  preceding  table  arranged  according  to  the  effective  tempera- 
tures and  the  lengths  of  time. 

Table  V.     Effective  temperatun  and  length  of  cocoon  stage  of  codling  moth. 


Average 

Total 

A\  .TIILM- 

Total 

Average 

Total 

tempera- 

tempera- 

Days. 

tempera- 

tempera- 

Days, 

tempera 

tempera- 

Days. 

ture. 

ture. 

ture. 

ture. 

ture. 

ture. 

o  y 

!■ 

°F. 

o  y 

o  y. 

°F. 

17 

209 

12 

■J."» 

604 

•_M 

2'.' 

l .  28 1 

I.". 

22 1 

i:; 

.M7 

21 

80 

:.:;:. 

18 

18 

•J  70 

15 

607 

28 

600 

20 

18 

802 

L6 

674 

26 

M 

194 

If. 

17 

•jo 

17 

a 

19 

581 

21 

666 

L8 

20 

641 

•l.\ 

666 

is 

1.;:: 

20 

1.171 

12 

722 

28 

26 

1,892 

19 

::-2 

IM 

16 

22 

156 

21 

29 

19 

■Ml 

17 

22 

615 

'21 

1^ 

28 

633 

22 

646 

20 

661 

28 

I.",:, 

11 

22 

698 

21 

88 

362 

11 

■_•:: 

7^:; 
1.  L15 

27 
88 

121 

13 

I'.- 

L9 

I.  170 

11 

1 

39 

From  the  table  we  tind  that  the  minimum  total  temperature  is  209  . 
the  maximum  1,392°,  and  the  average  592°.  The  evidence  given  )>y 
this  table  is  insufficient  to  warrant  any  definite  conclusions.  It  is 
quite  evident  that  there  are  other  factors  which  have  not  been  taken 
into  account,  of  which  moisture  and  unequal  development  of  the  larva? 
when  the  cocoon  is  spun  are  probably  the  most  important. 

EFFECT   OF   THE    INSECT    UPON    THE    FRUIT. 

The  effect  of  the  injury  by  the  codling  moth  upon  the  fruit  varies 
with  the  variety  of  the  fruit  and  the  season  of  the  year  in  which  the 
injury  iadone.  The  attack  of  the  larvae  of  the  first  generation  usually 
causes  the  fruit  to  fall.  A  few  of  the  fruits  of  fall  and  winter  varie- 
ties, after  having  been  injured,  stay  on  the  trees  for  the  remainder  of 
the  season,  but  the  early  varieties  fall  quite  rapidly  and  readily.  In 
all  cases  the  effect  of  the  injury  is  to  cause  the  fruit  to  ripen  prema- 
turely. The  amount  of  the  windfall  of'  the  late  varieties  depends  in 
great  measure  upon  the  amount  and  violence  of  the  wind. 

The  effect  of  the  injury  upon  the  value  of  the  fruit  is  variable.  If 
the  inside  of  the  fruit  is  eaten  out.  it  is  valueless  except  for  use  as 
cider  apples.  When  the  injury  consists  of  only  a  small  defect  on  the 
exterior  of  the  fruit,  it  may  be  graded  as  second,  and  is  of  considera- 
ble value.  Fruits  often  bear  very  small  spots  where  the  larva1  have 
pierced  the  skin  but  have  failed  to  bore  into  the  flesh  of  the  apple. 
These  spots  do  not  materially  injure  the  apple,  and  many  of  them  are 
packed  as  first-class  fruit.  In  cold  storage  apples  which  have  been 
injured  by  the  codling  moth  are  the  very  first  to  begin  to  rot.  and  are 
consequently  sources  of  contamination  to  the  surrounding  fruit. 

THE  PUPA. 

The  pupal  stage  of  the  codling  moth  is  that  stage  in  which  the 
organs  that  are  peculiar  characteristics  of  the  larva  arc  broken  down 
and  worked  over  into  the  tissue  of  the  adult.  The  pupa  is  about  half 
an  inch  in  length,  and  varies  in  color  from  yellow  to  brown,  depend- 
ing upon  age,  and  when  the  moth  is  about  to  emerge  it  has  a  distinct 
bronze  color.  The  head,  eyes,  mouth  parts,  antennae,  legs,  and  wings 
of  the  moth  are  apparent  in  sheaths  which  are  immovably  attached  to 
the  body.  The  abdominal  segments,  which  are  movable,  are  each 
armed  with  two  rows  of  spines,  except  the  terminal  segments,  which 
bear  only  one  each.  These  spines  point  backward,  and  play  an  impor- 
tant part  in  the  economy  of  the  insect.  The  last  abdominal  segment 
has  a  number  of  long  spines  with  hooks  at  the  end.  These  hooks  are 
fastened  in  the  silk  and  aid  the  pupa  in  holding  its  place  in  the  cocoon. 

EMERGENCE  OF  THE  MOTH. 

After  the  pupa  has  thrust  itself  out  of  the  cocoon,  the  pupal  skin 
splits  down   the  back,  and   the  moth  forces   its  way  out   by  splitting 


40 

away  the  bead  end  of  the  pupal  skin.  The  legs,  antenna',  and  wings 
arc  drawn  <>nt  of  their  sheaths.  The  insect  is  wet,  and  the  body  wall 
is  soft.     The  wings  Increase  several  times  in  size,  and  as  the  body  dries 

it  grows  more  rigid.  A  few  moths  were  observed  to  have  emerged  in 
the  field.  During  the  process  of  expanding  and  growing  they  (dung 
to  the  bark  of  the  trees  with  their  heads  up  (PL  VI,  fig.  I),  avoiding 
the  sunlight.  When  the  wings  were  fully  expanded  the  moths  would 
often  hold  them  over  their  hacks  for  a  few  minutes,  in  a  manner  simi- 
lar to  the  way  a  butterfly  holds  its  wings.  After  running  about  over 
the  tree  for  a  short  time  the  moths  fly  into  the  lower  branches  of  the 
trees,  and  are  lost  to  observation.  Their  quick  and  erratic  flight  is 
similar  to  that  of  other  moths  of  this  family.  The  whole  process  of 
emergence  takes  from  fifteen  to  thirty  minutes. 

THE  ADULT  INSECT. 

The  adult  insect  or  moth  is  quite  variable  in  size.  The  wings 
expand  from  14  to  19  mm.  Commonly  speaking,  they  never  expand 
over  three-fourths  of  an  inch.  The  whole  insect  is  covered  with  scales 
in  varying  colors.  The  tip  of  the  front  wings  bears  a  large  dark- 
brown  spot  or  ocellus  on  which  there  are  two  irregular  broken  rows 
of  scales,  which  have  a  coppery  metallic  color,  and  with  some  reflec- 
tions of  light  they  appear  golden.  Near  the  ocellus  there  is  a  very 
dark-brown  band  across  the  wing,  which  is  more  or  less  triangular  in 
outline.  The  remainder  of  the  wing  is  crossed  by  irregular  dark  and 
white  bands,  an  appearance  caused  by  the  white  tips  on  the  dark  scales. 
Jn  many  specimens  there  is  a  distinct  darker  band  across  the  wing, 
while  in  others  this  band  is  not  apparent.  The  hind  wings  are  a 
grayish-brown  color,  darker  toward  the  margin,  witli  a  long  black  line 
at  the  base  of  the  fringe.  The  underside  of  the  hind  wings  has 
dark,  irregular,  transverse  markings.  The  underside  of  the  front 
wings  is  of  a  light-brown  color,  with  opalescent  reflection  and  with  a 
few  markings  except  on  the  costa.  The  legs  and  head  and  patagia  are 
covered  with  long,  narrow,  white-tipped  scales,  while  the  body  is 
covered  with  white-colored  scales  with  opalescent  reflections.  The 
huge  white  scales  on  the  caudal  margin  of  the  abdominal  segments 
are  especially  conspicuous.      (PI.  VII.) 

HOW  TO  DISTINGUISH  THE  SEXES. 

There  are  many  characteristics  by  which  the  males  and  females  may 
be  easily  distinguished.  As  stated  byZeller,  the  males  have  penciled, 
long,  black  hairs  on  the  upper  side  of  the  hind  wings.  These  hairs  are 
Sometimes  of  a  light  color,  which  renders  them  difficult  to  distinguish. 
Slingerland  discovered  that  the  males  could  also  be  distinguished  by 
the  presence  of  a  distinct  elongate,  blackish  spot  on  the  underside  of 
tin-  fore  wings,  which  spot  consists  of  a  number  of  black  scales.     These 


41 

scales  are  sometimes  of  a  slate  color,  which  under  certain  lights  ren- 
ders the  spot  inconspicuous.  There  is  a  great  difference  between 
the  genital  organs  of  the  two  sexes,  as  the  ovipositor  of  the  female  can 
be  said  to  be  hoof -shaped,  and  ends,  roughly  speaking,  in  a  point; 
while  the  presence  of  the  claspers  on  the  male  can  be  said  to  cause  the 
abdomen  to  end  in  a  line. 

HABITS  OF  THE  MOTH. 

It  is  generalh'  stated  by  writers  that  the  adults  of  the  codling  moth 
are  but  rarely  seen  in  orchards.  In  cases  where  the  infestation  is  not 
very  bad  this  is  usually  the  case;  but  where  the  infestation  is  bad  it 
is  a  very  common  thing  to  see  the  moths  in  the  orchard,  but  never  in 
any  large  numbers.  They  spend  most  of  their  time  resting  on  the  upper 
surface  of  the  leaves  or  on  the  trunks  of  the  trees,  where  they  are 
hidden  by  their  resemblance  to  the  grayish  bark.  When  disturbed, 
they  fly  away  so  quickly  that  the  eye  is  unable  to  follow  them  in  their 
erratic  flight.  According  to  many  observers  the  codling  moth  feeds 
on  the  juice  of  ripe  apples.  The  writer  has  often  observed  them  drink- 
ing water  in  cages. 

As  the  conclusion  of  many  investigations  b}T  man}7  persons  and  under 
various  conditions,  it  has  been  definitely  determined  that  the  insect  is 
not  attracted  to  lights.  A  very  few  records  of  captures  of  codling 
moths  at  lights,  usually  of  the  accidental  catching  of  one  or  two 
specimens,  have  been  published. 

DURATION  OF  THE  LIFE  OF  THE  MOTH. 

LeBaron  gives  1  week  as  the  average  length  of  the  life  of  the  adult 
codling  moth.  Washburn  gives  from  10  to  15  days,  and  Slingerland 
says  that  one  moth  lived  in  his  cages  for  17  days.  Records  of  the 
writer  in  August,  1902,  of  forty-seven  moths,  show  that  two  moths 
lived  1  day;  ten,  2  days;  eleven,  3  da}\s;  ten,  -i  da}Ts;  two,  5  days;  seven, 
6  days;  one,  7  days;  two,  8  days,  and  two,  9  days;  giving  a  weighted 
average  of  -I  days. 

The  length  of  the  adult  stage  depends  upon  the  conditions  under 
which  the  moths  are  kept,  as  the}7  will  live  longer  if  there  is  water 
which  they,  can  drink.  The  average  of  4  days  was  obtained  when 
there  was  no  water  accessible  to  the  moths;  but  had  there  been  water 
or  ripe  fruit,  the  average  would  probably  have  been  longer. 

GENERATIONS  OF  THE  INSECT. 

The  question  of  the  number  of  generations  of  the  codling  moth  in 
one  season  has  for  many  years  been  in  doubt.  In  recent  years  ento- 
mologists have  been  stimulated  to  greater  efforts  and  have  in  a  measure 
solved  the  problem.  The  economic  importance  of  this  question  is 
very  apparent,  as  the  second  generation  of  the  insect  inflicts  about  ten 


4i> 

times  as  much  damage  as  the  first  generation,  and  it  is  necessary  to 
know  whether  a  second  generation  is  present  in  order  that  the  proper 
measures  of  control  may  be  employed.  Great  biological  interest  also 
attaches  to  this  problem,  as  it  affords  an  excellent  opportunity  for  the 
study  of  the  effects  of  different  climates  on  one  insect. 

The  term  "  generation"  is  used  instead  of  ••brood**  because  it 
describes  more  definitely  the  idea  intended.  A  generation  in  this  con- 
nection means  a  Dumber  of  individuals  which  pass  through  certain 
stages  at  about  tin-  same  time,  having  begun  in  the  same  stage  at  the 
beefinning  of  any  gfiven  season.  A  succeeding  generation  is  the  asrgrre- 
gate  of  all  the  different  broods  of  the  individuals  of  the  generation 
immediately  preceding,  A  new  generation  is  considered  to  begin  with 
the  egg  stage,  and  continues  through  all  the  transformations  of  the 
insect  until  the  moth  dies.  Many  authors  object  to  the  term  "partial 
generation,"  but  as  there  is  a  condition  in  which  this  term  can  be  used 
with  a  definite  meaning,  it  may  be  well  to  use  it.  For  instance,  in 
some  sections  of  the  country  all  the  insects  pass  through  one  genera- 
tion; a  few.  becoming  more  advanced  than  others,  may  succeed  in 
passing  through  the  pupal  and  moth  stages  and  lay  eggs,  from  which 
larvae  hatch  and  enter  the  fruit,  whereas  the  majority  of  the  insects 
hibernate  as  larvae  and  do  not  transform  until  the  following  spring. 
As  those  insects  which  enter  the  fruit  in  the  fall  do  not  for  the  most 
part  complete  their  development,  at  least  in  the  tield.  they  are  termed 
a  partial  generation. 

In  tabulating  the  results  of  observations  in  regard  to  the  time  of  the 
various  stages  we  find  that  at  certain  periods  more  individuals  of  a 
generation  are  in  certain  stages  than  at  other  times;  and  likewise  we 
find  periods  when  there  are  fewer  insects  of  a  certain  stage  than  at 
other  times.  These  periods  are  designated  respectively  the  maxima 
and  minima  of  the  different  generations.  It  is  always  considered  that 
the  larvae,  pupae,  and  moths  found  in  the  early  spring  belong  to  the 
last  generation  of  the  preceding  season  and  may  be  termed  the  hiber- 
nating generation. 

From  the  writings  of  European  authors  we  find  that  there  is  but 
one  generation  of  the  codling  moth  in  northern  Europe,  including 
England  (Westwood)  and  northern  and  central  Germany,  while  the 
evidence  of  Reaumur  and  Schmitberger  shows  that  at  Vienna  and  in 
France  there  are  two  generations.  American  writers  have  at  various 
times  recorded  many  observations  of  variations  in  the  number  of 
generations  in  the  United  States.  Fitch  seems  to  indicate4  the  pres- 
ence of  but  one  generation,  while  1  [arris  says  a  few  may  transform  and 
enter  the  fruit  in  the  fall,  though  the  majority  of  the  lirst  generation 
hibernate.  Fletcher  reports  that  careful  observations  extending  over 
ten  y.ar-  convince  him  that  near  Ottawa,  Canada,  there  is  but  one 
regular  generation  of  the  insect,  while  in  the  fruit-growing  districts 


43 

of  western  Ontario  there  are  two  generations,  the  second  being-  inva- 
riably the  more  destructive.  The  observations  of  Atkins.  Harvey, 
and  Munson  agree  with  those  of  Harris.  Slingerland  says  in  1898 
that  his  observations  indicate  that  in  New  York  a  large  number  of 
the  larvae  of  the  first  generation  develop  into  moths,  the  percentage 
transforming  depending  upon  the  weather  -conditions  of  the  season. 
In  1894  Smith  found  by  a  series  of  observations  that  the  larvae  col- 
lected in  midsummer  did  not  transform  further  that  year,  but  hiber- 
nated. Later,  in  1897,  he  states  that  near  New  Brunswick.  X.  J.,  there 
is  positively  only  a  single  annual  generation,  and.  further,  that  south 
of  Burlington  County  there  is  at  least  a  partial  second  generation. 
In  addition  to  the  observations  already  given  of  conditions  quite  simi- 
lar to  these  in  New  Jersey,  we  find  that  Trimble  in  1865  carried  out  a 
very  careful  and  accurate  series  of  experiments  upon  the  life  history 
of  the  codling  moth  at  Newark.  He  found  that  on  August  1"  there 
were  three  pupae  among  the  insects  under  observation,  and  that  on 
August  2<)  many  moths  had  emerged:  on  August  23  he  found  that  one 
in  live  of  the  larvae  had  transformed.  Sanderson  finds  that  there  is 
one  generation  and  a  partial  second  generation  in  Delaware.  He 
states  that  of  the  larvae  found  Jul}'  31  about  29  transformed  and  5 
remained  as  larva?.  Taking  these  numerous  observations  and  the  data 
given  in  regard  to  them  into  consideration,  we  must  conclude  that 
Doctor  Smith's  observations  are  too  few  in  number  and  do  not  justify 
the  assertion  that  there  is  but  one  generation  of  the  codling  moth  at 
New  Brunswick.  Man}'  observers  in  widely  different  sections  of  the 
United  States  have  found  two  generations  clearly  denned.  Le  Baron 
states  that  "  in  the  latitude  of  Chicago  a  great  majority  of  the  moths 
of  this  brood  (tirst)  emerge  the  last  two  weeks  in  July."  Riley,  after 
many  years  of  close  observation,  states  that  the  insect  is  "'invariably 
two  brooded  in  Missouri."  Popenoe  and  Marlatt  found  two  genera- 
tions in  Kansas.  Gillette  indicates  two  generations  in  Iowa.  Walton 
by  breeding  experiments  discovered  two  generations  in  che  same 
State.  From  a  series  of  observations  extending  over  several  years. 
checked  by  breeding  experiments.  Cordley  concludes  that  there  are 
two  generations  at  Corvallis,  Oreg.  Koebele  says  there  are  two  gen- 
erations in  the  Santa  Cruz  Mountains  of  California,  and  the  insect 
probably  does  not  differ  in  its  habits  throughout  the  State.  Based 
upon  one  of  the  most  extensive  studies  of  this  question  that  has  ever 
been  made.  Gillette  arrived  at  the  conclusion  that  there  are  two 
generations  in  Colorado.  Coolev  says  that  in  VM*'2  there  were  two 
generations  at  Missoula.  Mont.  Forbes  indicates  a  third  generation 
in  Illinois,  based  upon  the  fact  that  very  young  larvae  were  found  on 
October  1.  Coquillett  states  that  his  notes  indicate  that  the  insect 
has  three  generations  in  California.  Washburn  says  there  are  three 
to  four  generations  at  Corvallis,  Oreg.     Card  gives  two  to  four  in 


44 

Nebraska.  Cockerel!  concludes  there  are  three  lull  generations  near 
Mesilla  Park,  N.  Mex.  AJdrich  in  L900  stated  thai  there  were  three 
generations  in  Idaho,  and  in  L903  concluded  after  a  Beries  of  breeding 
experiments  that  there  was  a  partial  third  generation  at  Lewiston. 
At  various  times  writers  have  made  assertions  that  in  the  warmer 
sections  of  the  United  States  a  partial  fourth  brood  was  produced. 

In  carefully  sifting  all  these  statements  the  writer  finds  many  points 
which  throw  doubt  upon  and  render  them  of  hut  little  value,  principally 
because  definite  date-  and  localities  are  not  given.  The  date  and  exact 
localities  are  often  of  as  much  importance  to  future  workers,  and  per- 
haps of  more  importance,  than  the  observation  it-elf. 

METHODS    I'.V    WHICH     THE     NUMBER    OF   GENERATIONS     MAI     BE 

DETERMINED. 

From  the  nature  of  the  case  the  determination  of  the  number  of 
generations  of  the  codling  moth  is  a  most  difficult  problem  to  solve 
accurately.  The  methods  used  must  he  scrutinized  carefully,  and  all 
possible  sources  of  error  mu-t  he  taken  into  consideration  or  elimi- 
nated. The  correctness  of  a  conclusion  can  he  assured  only  by  exact- 
ness in  methods  and  hv  corroborative  evidence  secured  by  different 
methods.  Observations  made  in  orchard  examinations  have  constituted 
one  of  the  methods  largely  followed.  Although  observations  are  of 
great  value  when  used  in  connection  with  other  methods,  they  often 
lead  to  erroneous  conclusions  when  used  alone,  as  it  i-  possible  to 
obtain  evidence  of  the  condition  of  an  orchard  only  from  the  study  of 
a  very  small  portion  of  it  during  a  very  short  period.  Past  conditions 
are  often  unknown,  and  conclusions  obtained  are  largely  based  14)011  pre- 
conceived ideas.  If  a  large  number  of  insects  can  he  bred  throughout 
the  season,  much  valuable  data  can  he  secured  and  the  problem  solved 
beyond  any  doubt.  A-  yet  we  have  no  records  of  breeding  experiments 
carried  on  throughout  the  season  with  the  necessary  accurate  data. 
The  writer  ha-  attempted  many  times  to  breed  the  insects  throughout 
the  season,  but  has  always  failed,  usually  on  account  of  some  unfore- 
seen difficulty  which  caused  the  experiment  to  end.     However,  it  is 

believed    that   with    proper   care   and    experience   thi-   breeding  can  he 

successfully  done.  Breeding  the  insect  and  harmonizing  the  results  of 
the  breeding  hy  observations  in  the  orchard-  ha-  been  the  method 
most  used  in  working  upon  this  question.  By  breeding  the  insect 
through  part-  <>f  it-  generations  valuable  data  have  been  secured, 
which,  if  pieced  together  and  corroborated  by  other  methods,  are 
almost  a-  valuable  as  if  the  insect  bad  been  bred  throughout  the  season. 
Many  entomologists  have  neglected  t<>  increase  the  value  of  their 
breeding  experiments  by  keeping  the  insects  under  condition-  of  tem 
perat  lire  and  moisture  different  from  those  prevailing  in  the  orchard 
and  keeping  no  record  or  a  very  fragmentary  record  of  the  tempera- 


45 

tures  to  which  the  insects  were  subjected.  Many  other  records  are 
questionable  by  reason  of  the  fact  that  the  generation,  or  the  nearness 
to  the  maximum  of  the  generation,  of  the  insects  placed  in  the  cage 
was  uncertain  or  unknown. 

Early  in  his  studies  of  the  life  history  of  this  insect  the  writer  saw 
the  necessity  of  finding  some  method  by  which  the  numbers  of  indi- 
viduals of  a  generation  could  be  approximated  at  certain  times.  By 
an  incidental  study  of  the  records  of  larvae  captured  under  bands, 
published  by  Professor  Aldrich  in  1900,  it  was  noted  that  at  a  certain 
time  in  the  season  there  were  fewer  larvae  so  caught  than  at  periods 
of  time  immediately  following  and  preceding.  By  collecting  as  many 
records  as  were  obtainable  at  that  time,  it  was  observed  that  these 
conditions  were  quite  constant.  The  periods  of  the  larger  and  smaller 
number  were  termed,  respectively,  the  maximum  and  minimum  of 
larva?  entering  bands. 

In  1901  many  fruit  growers  in  Idaho,  at  the  request  of  the  writer, 
kept  and  submitted  records  of  the  larva?  killed  under  bands.  Other 
records,  many  of  which  had  been  made  without  any  idea  of  the  future 
use  to  which  they  might  be  put.  were  collected  from  many  sources. 
These  records  were  tabulated  and  curves  were  drawn  upon  cross-see- 
tion  paper,  using  the  time  as  one  factor  and  the  number  of  larvae  as  the 
other.  These  curves  give  quite  an  accurate  picture  of  the  course  of  the 
insect  in  the  orchards  throughout  the  season.  Not  all  of  the  records, 
however,  were  satisfactory,  as  a  few  of  them  from  various  causes  gave 
data  which  were  of  no  value.  The  curve  showing  the  effective  tem- 
perature at  the  dates  at  which  the  larva?  were  killed  under  the  bands 
was  drawn  upon  the  same  charts  and  gives  quite  accurately  the  effect 
of  the  temperature  upon  this  habit  of  the  insect.  A  number  of  these 
records  are  reproduced  (tigs.  5  to  16). 

INACCURACIES    OF   THE    RECORDS. 

There  are  many  sources  of  possible  inaccuracy  in  these  records. 
The  greatest  inaccuracy  is  probably  found  in  the  weekly  or  biweekly 
band  records,  because  these  are  composite  records  of  many  individual 
trees  and  show  only  approximately  the  dates  of  the  maxima  and  min- 
ima. Many  of  the  records  were  commenced  too  late  in  the  season  to 
be  of  any  real  value:  and  when  they  were  started  even  a  little  late  the 
curve  ascends  with  rapidity,  which  would  not  have  happened  had  the 
record  been  started  earlier.  In  consequence  of  a  series  of  warm  days. 
the  maximum  number  of  larva?  may  enter  the  bands  sooner  than  they 
would  if  the  temperature  had  remained  normal;  and  if  the  temperature 
be  low  for  many  days,  the  maximum  might  be  later  than  it  would  be 
normally.  Spraying  might  seriously  interfere  with  the  accuracy  of 
the  record,  as  at  certain  periods  all  of  the  larvae  entering  the  fruits 
might  be  killed  and  thus  cause  a  fall  in  the  curve  of  larvae  entering 


4f> 


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hands.     When  counted  the 

|  larvae   were   killed,   which 

|  reduced    the     number   of 

a  larva-    of    the    succeeding 

a  generation.      If    the    tree 

1  from  which  the  record  is 
«  taken  should  he  covered 
e  with  rough  bark  or  have  a 
|  Large  Dumber  of  holes  and 

2  cracks  in  it,  the  number  of 
|  larva-  entering  the  bands 
§  will  not  be  so  great  as  if 
^  the  hand  were  the  only 
|  place  in  which  they  could 
2  hide  to  spin  their  cocoons: 
>  therefore,  filling  the  holes 
®  and  scraping  away  the 
g  rough  bark  would  cause  a 

*  rise  in  the  curve. 

In  most  cases  the  con- 

%  ditions   which   would  ren- 

y,  der  the  records  inaccurate 

.  were    eliminated    when   it 

|  was  possible  to  do  so.     In 

J  order  to  show  the  relations 

|  between  the  daily  and  the 

g  weekly    band    records,    a 

=  weekly    summary    (tig.   6) 

J  was  made  of  Gibson's  daily 

5  hand  record.  By  this 
|  means  it  was  shown  that 
|  the  weekly  records  are 
|  only  approximate,  and 
|  show  the  general   trend  of 

6  the  insect  in  tin-  orchard 
J  rather  than  any  details. 
~  One  writer  has  suggested 
|  that  the  rise  and  fall  of 
t  the  temperature  would 
|  cause  a  coi-responding  rise 
|  and  fall  in  the  Dumber  of 

*  larvss,  so  as  to  obscure  the 
|  true  position  of  the  maxi- 
I.  mum.      By  a  study  of  the 

record  made  by  Mr.  ( rib- 
son  (fig.   5),  in  which  the 


effective  temperature  is  shown  by  a  dotted  line,  many  interesting-  facts 
in  regard  to  the  temperature  can  be  observed.  It  must  be  noted, 
however,  that  the  number  of  larvae  caught  on  any  given  day  is  influ- 
enced by  the  temperature  of  the  preceding  day.  as  most  of  the  larva? 
enter  the  bands  at  night,  some  time  before  midnight,  and  that  they 
are  usually  killed  and  counted  some  time  the  following  morning, 
while  the  observations  upon  the  temperature  were   taken  at  6  a.  m. 


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JULY                                                          AUG JST   _ 

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Fig.  6. — Weekly  summary  of  Mr.  Gibson's  band  record. 

and  6  p.  m.  The  great  rise  which  occurred  on  June  24  was  probably 
due  in  a  great  measure  to  the  fact  that  the  bund-  were  placed  upon 
the  trees  on  the  21st.  The  fall  in  the  number  of  larvae  on  June  24, 
the  rise  on  June  lj7.  the  fall  on  June  30,  the  rise  on  July  1  and  2.  and 
the  fall  on  July  4  can  be  partially  accounted  for  by  the  corresponding 
rise  and  fall  of  the  temperature.     From  about  July  5  to  August  4  the 


Fig.  7. — Band  record  made  by  William  A.  George.  Caldwell.  Idaho,  In  1901. 

temperature  was  high,  but  there  was  no  corresponding  rise  m  the 
number  of  larvae,  as  there  were  no'  larva?  ready  to  enter  the  bands,  the 
majority  of  the  insects  being  in  the  moth.  egg.  and  younger  larval 
stages.  Thi-  interval  of  few  larva?  marks  the  time  between  the 
maxima  of  the  generations  entering  the  bands.  In  the  second  maxi- 
mum it  can  be  noted  that  the  rise  and  fall  of-  the  number  of  larva?  is 


48 

usually  parallel  with  thai  of  the  temperature,  but  toward  the  end  of 
the  record  the  temperature  has  but  little  influence.     The  record  made 

l.\    Mr.  George  (fig.  7)  and   Mr.   Ajers  (figs.  8  and  9)  -how  practically 


N 

BO 

a 
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i 

JULY 

AUGUST 

SEPT 

■6ct. 

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8.— Weekly  band  record  made  by  Mr.  Aver-  at  Boise,  Idaho,  in  1897,  on  140  trees. 

the  Same  conditions,  but   not  so  (dearly,  on  account  of  the   length  of 
time  between  the  observations. 

LENGTH    OF   THE    LIFE    CYCLE. 

In  order  to  establish  a  correct  basis  for  the  determination  of  the 
number  of  generations,  it  is  essential  that  we  determine  as  closely  as 


Pio.  v.  -Band  record  made  by  Mr.  Avers  in  li 

possible  the  average  Dumber  of  days  in  which  the  insect  can  pass 
through  one  generation.  Assuming  a  certain  date,  with  as  much 
accuracy  as  possible,  when  the  maxima  (n-cuv  in  a  hand  record,  and 
taking  into  consideration  all  the  imperfections  of  the  records,  we 
should  have  approximate!}'  in  the  number  of  days  between  these  max- 


3,     4"    D  v.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  VI. 


Fig.  1.— Larv>£.  Pup>e.  and  Moths  on  Rough  Bark. 


Fig.  2.— Infested  Apples  Being  Buried. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  VII. 


Fig.  1.— Codling  Moth  'Enlarged  4  Times1. 
Wing  on  the  right  shows  the  reflections  from  the  gold-colored  scales  in  the  ocellus. 


Fig.  2.— Codling  Moths  (Enlarged  Twice] 


w^ti0mm     ^|i(i|l      IjHeIjUJJ 


Fig.  3.— Codling  Moths  (Natural  Size,  from  Slingerland^ 


49 

ima  the  length  of  the  life  cycle  of  the  insect.  In  the  records  given 
we  find  that  the  periods  vary  from  40  to  about  66  days,  with  an  aver- 
age of  55  days,  or  about  8  weeks.  Professor  Gillette  finds  thp' 
according  to   his  life  history  studies  upon  the  summer   brood   the 


?:■:: 
:-:: 

Z30C 

:::: 

::: 

mr 


JULY 


AUGUST 


SEPT. 


Fig.  10.— Band  record  made  by  David  Brothers  in  Colorado  in  1S99. 

period  of  the  different  stages  is  as  follows:  From  egg  to  larva.  7 
days:  from  larva  to  cocoon  stage.  19  days;  from  cocoon  stage  to  emer- 
gence of  moth.  18  days:  from  emerg'ence  of  moth  to  middle  of  egg- 


Fig.  11.— Band  record  published  by  Prof.  C  P.  Gillette,  taken  on  14  trees,  at  Fort  Collins,  Colo.,  in  1900. 

laying  stage.  5  day-  (estimated);  total,  4:9  days,  or  V  weeks.     From 
the  writer's  numerous  records  of  the  lengths  of  the  different  stages, 
however,  it  is  found  that  most  are  somewhat  longer  than  those  given 
6514— No.  41—03 4 


50 

by  Professor  Gillette  and  thai  the  egg  stage  averages  about  11  days; 
from  th<>  hatching  of  larvae  to  Leaving  the  fruit,  20  days;  from  enter- 
ing the  bands  to  emergence  of  moth.  22  days;  from  emergence  of  moth 
to  middle  of  egg  laying  (estimated).  5  days;  making  a  total  of  58  days, 
or  about  8  weeks.  By  adding  together  the  shortest  times  and  the 
longest  times,  respectively,  we  find  the  minimum  length  of  the  life 
cycle  to  be  36  days  and  the  maximum  LOO  days.  This  period  of  55  to 
58  days  having  been  obtained  by  these  two  widely  different  methods, 
they  are  probably  not  far  from  the  correct  average  length  of  the  life 
eycli-  of  the  codling  moth. 

SEASONAL  HISTORY. 

By  following  the  development  of  the  codling  moth  through  the  sea- 
son as  carefully  as  possible,  we  are  enabled  to  throw  more  light  upon 
the  question  of  the  number  of  generations.  Those  larvae  which  have 
escaped  their  enemies  during  the  winter,  if  left  in  the  tield.  change  to 


Fig.  12.— Band  record  made  by  Prof,  J-'.  A.  Popenoe,  Manhattan,  Kans.,  in  isoo. 

pupa-,  according  to  Slingerland,  just  prior  to  the  time  when  the  apple 
trees  are  in  bloom.  He  found  the  first  pupae  April  27,  and  by  the  7th 
of  May  about  one-fourth  had  pupated.  In  L902  the  writer  found  the 
largest  number  of  pupae  about  the  time  the  apples  were  in  bloom. 
Some  were  found  in  rotten  wood  as  late  as  June  10.  The  location  of 
the  larva  has  the  greatest  influence  upon  the  period  of  pupation,  those 
in  warmer  places  pupating  more  quickly  than  those  in  colder  situations. 


EMERGENCE  OF  THE  MOTH. 

From  the  records  of  various  writers,  as  compiled  bv  Gillette,  we 
find  that  the  first  moths  appeared  from  April  24  in  New  Mexico  to 
about  Mav  L6  at  Corvallis,  Oreff.     Mr.  McPherson  records  that  in  L901 

he  found  a  moth  in  the  field  in  Idaho  as  early  as  April  23,  and  that 
the  moths  were  most  numerous  about  May  1.  Mr.  Hitt  in  breeding 
50  moths  found  that  tin-  first  emerged  May  5  and  the  last  May  28.     In 

L902  the  writer  found  that  the  majority  of  the  moths  emerged  between 


51 


May  15  and  2<  >.  Cordley  states 
that  in  Oregon  in  1899  moths 
emerged  in  some  eases  April 
10,  and  continued  to  do  so  until 
July  1.  At  Ithaca.  N.  Y.. 
Slingerland  found  in  1896  that 
moths  emerged  from  May  3  to 
June  22,  and  in  189^  from  May 
24:  to  June  7.  Gillette  records 
that  he  found  moths  out  of 
doors  at  Fort  Collins  as  early  as 
April  2o.  The  extreme  range 
in  time  of  appearance  of  these 
moths  was  69  days  in  their 
cages.  At  Fort  Collins,  ac- 
cording to  Mr.  Hitt's  records, 
this  period  extends  over  about 
23  days.  Professor  Slinger- 
land found  that  this  range  was 
49  days  in  1S96. 

RELATION  BETWEEN  EMER- 
GENCE OF  THE  MOTH  AND 
THE  BLOOMING  PERIOD. 

Slingerland  states  that  the 
moths  begin  to  emerge  in  New 
York  about  the  time  the  apples 
are  in  bloom,  but  the  majority 
do  not  emerge  until  after  the 
blossoms  fall,  and  but  few  lar- 
vae are  found  to  enter  the  fruit 
until  about  two  weeks  there- 
after. Gillette  found  the  first 
moth  emerging  about  10  days 
before  the  trees  were  in  bloom. 
He  states  that  the  majority  of 
them  emerged  about  the  time 
of  bloom,  but  effffs  were  found 
July  9,  1900,  and  June  19, 
1901,  and  were  all  hatched  by 
July  21,  the  trees  having  been 
in  blossom  about  May  5  to  15. 
This  would  make  about  a 
month  between  the  blooming 
period  and  the  time  when  the 


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52 

first  larvae  hatch  and  enter  the  fruit.  Card  found  the  eggs  about 
three  weeks  after  the  blossoms  had  fallen.  Cordley  found  that  in 
L898  the  first  larva  entered  the  fruit  about  July  L  the  egg  from  which 


JULY                                                   AUGUST                                                  SEPT.                                   OCT. 

2C« 

2301 

24O0 

2300 

2200 

2KM 

900 

800 

y\ 

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too 

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200 

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1 

Fie  1 1.— Band  record  Diade  by  Prof.  J.  M.  Aldrich,  Juliaetta,  Idaho,  on  10  trees,  in  1899. 

it  hatched  having  probably  been  deposited  about  June  21.  This  enter- 
ing of  the  fruit  took  place  about  two  months  after  the  petals  had 
fallen.  The  writer  found  that  in  southern  Idaho  in  1902  the  apples 
were  in   full  bloom   about   May  L3,  and  the  first   larvae  were  noted  to 


•    ■    :  •        ; I ! ;  ■  ■  ■ ;  14  1 4 1  f-  r  •  t  1     ■••{•■ 


Fio.  15.— K  taeof  the  recorda  made  by  u   E.  Burke  al  Boise,  [daho,  In  vac.  to  determine  the  maximum 

o4  the  second  generation. 

have  entered  the  fruit  June   LI,  or  about  25  days  after  the  blossoms 

had  fallen. 

From  these  few  observations  we  find  that  the  moths  may  emerge 
-Mine  time  before  the  apples  are  in  bloom,  and.  depending  largely 


53 

upon  locality,  the  larvae  begin  to  enter  the  fruit  from  a  week  to  two 
months  after  the  blossoms  have  fallen.  From  the  standpoint  of  the 
orchardist  this  is  a  most  important  question  in  considering  the  effect 
of  the  first  spraying  upon  the  insect. 


Fig.  16.— Record  by  H.  C.  Close,  Utah  Agricultural  College. 

The  next  point  at  which  we  can  make  any  definite  observations  upon 
the  codling  moth  is  when  the  larva1  are  leaving  the  fruit  and  entering 
the  bands  for  the  purpose  of  spinning  their  cocoons.  The  band  rec- 
ords give  this  most  valuable  data  in  a  very  accurate  manner.  The 
following  tabic  shows  the  maximum  of  the  different  generations  enter- 
ing  the  bands,  according  to  these  records: 

Table  YI. — Maximum  of  larva  hilled  under  hands. 


Year. 


1897 
1898 

1 899 
1901 

1901 
1901 
1901 
1901 

1901 
1901 
1901 
1901 
1901 
1899 
1*90 
1883 


Locality. 


Observer  or  source 
of  record. 


First 

maxi- 
mum. 


* 
£ 


Boise.  Idaho 

do 

Juliaetta,  Idaho.. 

Nampa,  Idaho 

Payette,  Idaho  ... 

do 

do 

I'rovo.  Utah 


....do 

do 

Hagerman,  Idahi 
Lewiston,  Idaho. 
Caldwell,  Idaho. 

Colorado 

Kansas 

.-an  Jose,  Cal 


Second 

maxi- 
mum. 


Mr.  Avers 

....do 

l'rot'.J.M.  Aldrich 

H.  G.  Gibson 

J.  Shearer 

do 
....do 
Utah  Agricultural 
College 

do 

do 

It.  E.  Connor 

s.  G.  Iasman 

Wm.  C.  George  ... 
David  Brothers... 

K.  A.  Poponoe 

Chapin 


140  July    17      Sept.  15 

1-10  July    10      Sept.  10 

40  July  20     sept.  24 

4  June  26     Aug.  16 

3  July  is     Aug.  17 

80  July     1 

128  July     5 

23. ...do... 


26  July   13 
34  July     5 

27  July  12 

4  ....do... 

10  June  25 

July   16 

July   25 

850  July   19 


Aug.  30 

Sept.    2 

Aug.  27 
Sept.  2 
Sept.  4 
Sept.  10 
Aug.  13 
Sept.  15 
Sept.  28 
Sept.  23 


—  y 
a  = 


Time  of  re- 
moval of 
bands. 


< 


6112. 
62  20. 
66   8, 
51 
60 
61   3, 


45  2 
50  2 
54 

00 
49 

01  .. 
65.. 


247   Weekly.... 

909 do 

620 do 

467    Dailv 

215    Weekly.... 

554 do 

690 do 

141 do 

829 do 

880 do 

194 do 

660  6  per  month 
640  2  to  5  days . 
...   Weekly.... 

do* 

do 


87.48 

149.  36 
215.  5C 
116.  75 
71.66 
44.  42 
13. 2 
180 

108. 2 

84.7 

8.2 

166.6 
64 


54 

Rile}  states  thai  the  larvae  of  the  first  generation  are  most  abundant 
about  July  8;  Gillette,  that  this  occurs  in  Grand  Junction  about  July 
L5,  at  Denver  July  21,  and  at  Fort  Collins  July  'I'k 

Mollis   OF   THE    FIRST   GENERATION. 

Card  round  the  first  moths  of  this  generation  about  July  '2.  Cord- 
ley  gives  A.ugus(  1  as  the  date  for  the  first  and  September  L5  for  the 
last.  Gillette  gives  the  following  data:  Grand  Junction,  Colo.,  first 
July  28,  Last  September  L2;  Canyon  City,  first  July  L5,  last  Septem- 
ber LO;  Fort  Collins,  first  July  13,  last  September  L2.  According  to 
Gillette,  the  eggs  of  the  first  generation  were  most  abundant  August 
L2.  In  L901  the  writer  found  eggs  most  abundant  between  July  L5 
and  August  1.  In  L902  they  were  most  abundant  about  the  same  time, 
but  were  obtained  in  caged  as  late  as  August  29.  The  dates  of  the 
maxima  of  this  generation  of  the  larvae  going  under  bands  is  wrll 
shown  in  Table  V]  for  the  second  generation.  An  examination  of  these 
band  records  as  published  shows  that  the  period  of  the  larvae  leaving 
the  fruit  and  entering  the  bands  extends  over  two  months. 

HIBERNATION. 

The  following  table  by  Gillette  shows  the  time  at  which  pupation 
ceased  and  the  larvae  began  to  hibernate  at  various  places  in  Colorado. 
It  was  found,  as  shown  by  the  table,  that  pupation  ceased  between 
August  1<>  and  August  :i<>.  varying  with  the  locality  in  which  the 
experiments  were  made. 

Table  VI  [.—Proportion  of  hibernating  larva  taken  at  different  <htt,s. ' 


Localil  v 


Grand  Junction, Colo. 

Do 

I»«. 

I'- 

1>«. 

Do 

Do 

Rockyi  ord,  Colo 

I'- 

I).. 

Dm 

I'M 

I'" 

Canyon  Clty.Colo.... 

!»<• 

!»-• 

]>■■ 


I>;itrs  larvae  were  taken. 


July  16-23,1900 

July  24-30, 1900 

July31-Aug.  •'..  1900 

Aug.  6-13,  L900 

am-.  13  20,  r.tiMi 

Aug.21  

Aug.  30  Sept.  1,1900 

Aug.  1  6,  1900 

Aug.  7-11, 1900 

Aug.  12  II.  1900 

Aug.  L5  21, 1900 

AUg.  22  28,  1900 

Aug.29-Sept.6,1900 

July  30,  1899 

Au-.  1-13,  L899 

Aug.  II  20,1899 

Aug.  21-28,  1899 


Number 
taken. 


79 
ISO 

l '.»■_> 

II 
:.i 

11. "» 
B0 
26 
70 
60 

L00 


Number 
hibernat- 
ing. 


78 
130 
192 

I 
II 
66 
115 
30 
0 

so 

II 


Record  by- 


Silmou  Smith. 

Do. 

Ii... 

Do. 

Do. 

Do. 
II.  B. Griffin. 

Do. 

Do. 

Do. 

D... 

Do. 
Dr.  K..I.  Peare. 

Do. 

Do. 

Do. 


Cordley  has  for  several  years  been  unable  to  breed  any  moths  after 
September  L5.  In  L900  the  writer  found  that  pupation  had  ceased 
September  1.  and  in  L901  September7.     In  L  902  more  extensive  breed- 

sperimente  were  carried  out.  from  which  it  was  found  that  pupa- 
tion began  t<»  grow  less  aboui  A.ugus1  l  and  entirely  ceased  August 
l'i'.  and  that  no  moths  emerged  after  September  17. 


55 

At  various  times  records  have  been  made  of  tin  ding-  single  moths 
late  in  the  season,  in  October.  The  presence  of  these  moths  can  be 
easily  accounted  for  by  the  fact  that  the  larva-  probably  got  into  some 
place  where  the  general  outside  temperature  had  no  effect  on  them, 
and  increased  temperature  caused  transformation. 

EVIDENCES  OF  A  THIRD  GENERATION. 

It  is  often  found  that  in  September  a  large  number  of  the  fruit- 
have  been  entered  by  very  young  inject.-,  and  it  is  also  found  that  in 
some  localities  these  injuries  extend  into  October.  This  has  given  rise 
to  the  belief  that  there  is  a  third  generation  present:  and  not  having 
detinite  records  in  regard  to  the  life  history  of  the  codling  moth,  many 
fruit  growers  have  come  to  the  conclusion  that  there  are  three  gener- 
ations, and  some  have  even  gone  so  far  a-  to  say  that  there  is  a  par- 
tial fourth  generation.  Many  entomologists  have  taken  these  state- 
ments from  the  fruit  grower.-,  and  not  having  given  as  complete  study 
to  the  subject  a-  was  possible,  have  published  the  conclusion  that  three 
generations  were  present.  The  writer  has  collected  all  of  the  publi- 
cations in  which  three  generation-  were  either  indicated  or  given  as 
occurring,  and  has,  with  the  greatest  of  care,  studied  the  observations 
upon  which  the  conclusions  were  based.  Many  entomologists  have 
submitted  original  notes  or  copies  of  the  notes  from  which  their  con- 
clusion- were  drawn.  After  carefully  studying  all  these  records  and 
published  accounts  the  conclusion  was  reached  that  there  were  only 
two  publications  in  which  any  substantial  evidence  is  given  as  to  the 
exi-tence  of  a  third  generation  of  the  codling  moth.  Professor  Cock- 
erell.  in  a  bulletin  of  the  New  Mexico  Experiment  Station,  concludes 
that  there  are  three  generations  and  a  partial  fourth.  Professor  Cock- 
erell  relied  mainly  upon  observations,  and  checked  these  observations 
by  breeding  experiments  in  only  a  few  instances.  The  observations, 
while  of  value,  give  the  condition-  in  the  orchard  at  irregular  inter- 
val-, and  then  only  for  a  very  short  period  of  time.  Many  erroneous 
conclusions  were  drawn  from  these  observations.  For  instance,  the 
finding  of  an  empty  pupa  case  on  June  26  was  considered  an  evi- 
dence that  the  moths  of  the  first  generation  had  emerged.  In  view  of 
the  fact  that  Professor  Gillette  finds  that  the  extreme  period  of  emer- 
gence of  the  moths  in  the  spring  is  69  days  at  Fort  Collins,  and  that 
Professor  Slingerland  found  moth  in  New  York  as  late  as  June  22.  we 
see  that  there  is  the  greatest  probability  that  these  moths  were  the 
latter  part  of  the  hibernating  generation,  instead  of  the  first  part  of 
the  first  generation.  The  finding  of  wormy  apples  on  July  3  was  con- 
sidered as  the  beginning  of  the  second  generation  entering  the  fruit. 
On  August  1l'  -mall  larva?  in  fruit  were  considered  to  be  the  beginning 
of  the  third  generation.  Anyone  familiar  with  the  conditions  of 
Western  orchards  know-  that  small  larva?  entering  the  fruit  can  be 


56 

found  almost  ;mv  time  in  the  summer.  From  the  evidence  given  by 
Professor  Cockerel]  the  writer  is  of  the  opinion  that  there  are  only 
two  generations  of  the  insect  present  in  Mesilla  Park,  and  that  there 
i-  no  sufficient  evidence  of  a  third. 

Professor  Aldrich  in  a  recent  bulletin  state-  that,  in  his  opinion, 
there  is  at  least  a  partial  third  brood  at  Lewiston,  Idaho.  Th is  con- 
clusion is  arrived  at  as  a  result  of  some  very  carefully  conducted 
experiments  which  give  evidence,  by  breeding  records,  which  up  to  a 
certain  point  is  Indisputable.  By  caging  the  insects  at  proper  inter- 
vals Professor  Aldrich  obtained  moths  of  the  second  generation  on 
September  3  and  4.  There  is  no  doubt  in  the  mind  of  the  writer  that 
these  were  moths  of  the  second  generation.  But  Professor  Aldrich 
failed  to  state  whether  or  not  he  obtained  eo-o\s  from  these  moths,  and 
instead  of  doing  so  took  unknown  field  conditions  to  carry  out  the 
remainder  of  his  experiments,  taking  it  for  granted  that  the  larvae 
entering  after  September  6  hatched  from  eggs  which  had  been  laid  by 
moths  of  a  similar  age  to  those  emerging  September  3  and  4.  As  the 
latter  were4  of  the  very  earliest  of  the  second  gen  ration,  there  is  no 
reason  for  assuming  that  the  larvae  which  entered  after  this  time  were 
not  larvae  of  the  retarded  portion  of  the  second  generation.  By  using 
the  Length  of  the  life  cycle  with  the  data  given  it  is  obvious  that  these 
larvae  belong  to  the  second  generation  instead  of  a  third. 

CONCLUSION. 

By  taking  into  consideration  the  evidence  which  has  been  derived 
from  the  hand  records,  from  breeding  experiments,  and  observation, 
the  writer  ha-  no  hesitancy  in  concluding  that  there  are  but  two  gen- 
erations of  the  codling  moth  in  the  arid  sections  of  the  West,  and  that 
it  remains  to  he  proven  that  even  a  partial  third  generation  of  the 
insect  is  present  in  any  part  of  the  United  States.  The  writer  admits, 
however,  the  possibility  of  a  partial  third  generation  in  the  West  and 
South,  and  that  careful,  accurate  work  in  tin4  future  will  give  us  bet- 
ter evidence  upon  this  point  and  settle  the  question  beyond  a  doubt. 
By  a  careful  study  of  the  temperatures  for  several  years  in  the  locali- 
ties where  observations  have  been  made  upon  the  number  of  genera- 
tions of  the  insect,  the  writer  hoped  to  be  able  to  give  the  total 
temperature  at  which  the  different  conditions  in  regard  to  the  genera- 
tions might  occur;  but  after  a  great  amount  of  labor  this  was  found 
to  be  Impracticable,  principally  on  account  of  insufficient  accurate 
observations  upon   the   insect,  and   it  was  decided   to  make  use  of  the 

more  general  life  /ones  in  determining  tin1  distribution  of  genera- 
tions. It  may  be  stated  that  the  boundaries  between  these  life  zones 
are  only  approximate;   that   there  are  different  gradations  between 

them,  and  that  as  yet  there  are  many  inaccuracies  in  the  ma]).  Mr. 
Mai  latt.  from  persona]  experience  and  the  observations  of  other  ento- 


57 

niologist-.  arrived  at  the  conclusion  that  there  was  one  generation  of 
the  insect  in  the  transition  zone,  two  in  the  upper  austral,  and  three  in 
the  lower  austral.  By  using  the  conclusions  of  recent  years  the  writei 
finds  that  there -is  one  generation  in  the  transition  zone,  with  often  a 
partial  second,  two  generations  in  the  upper  austral,  and  two  in  the 
lower  austral,  with  a  possibility  of  a  partial  third. 

NATURAL    CONDITIONS  WHICH   TEND    TO    DECREASE   NUMBERS. 

It  has  often  been  noted  that  a  sudden  fall  of  temperature  is  fatal  to 
a  large  number  of  the  smaller  larvae  of  the  codling  moth.  It  has 
been  already  noted  that  Professor  Aldrich  has  recorded  such  an  obser- 
vation. Hot  sunshine  and  extreme  dryness  cause  many  of  the  pupa? 
in  the  case  to  die.  A  moist  climate  aids  fungi  and  bacteria  to  such  an 
extent  that  sometimes  most  of  the  larvae  are  killed  by  them.  Larva1 
that  are  killed  by  fungous  diseases  are  hard  and  mummified,  and 
have  a  whitish  appearance.  Bacteria  cause  the  internal  organs  to  dis- 
integrate and  the  larva  to  become  limp  and  full  of  juices  of  a  brown 
color. 

NATURAL  ENEMIES.     ' 

Although  the  codling  moth  ha-  many  natural  enemies,  the  number 
impared  with  those  of  other  Lepidopterou-  larvae  is  comparatively 

small.  This  may  be  accounted  for  by  the  fact  that  the  insect  through- 
out the  greater  part  of  it<  life  i<  more  or  less  protected,  but  when  the 
larvae  have  left  the  fruits  and  are  seeking  places  in  which  to  spin  their 
cocoons  and  when  in  the  winged  stage  they  are  attacked  by  numer- 
ous enemies.  Birds  are  by  far  the  most  efficient  natural  enemies  of 
this  insect.  Anyone  who  tries  to  collect  the  larvae  from  the  trunks  of 
trees  in  spring  will  find  very  few  specimens,  but.  on  the  other  hand, 
will  rind  many  empty  cocoons.  The  writer  has  many  times  in  the 
spring  searched  persistently  for  larvae  in  the  rough  bark  and  the  more 
exposed  crack-,  but  found  practically  none,  although  many  could  be 
secured  by  cutting  into  the  holes  and  cracks  of  the  tree.  Riley. 
Walsh,  and  Slingerland  also  note  this  effectiveness,  and  the  amount  of 
good  the  birds  do  can  only  be  estimated.  The  cocoons  are  always 
found,  and  on  a  close  inspection  of  the  bark  a  telltale  hole  disclose^  the 
story  of  some  woodpecker's  work.  It  has  often  been  noted  also  that 
the  same  birds  have  made  holes  or  enlarged  the  cracks  in  the  stubs  of 
old  branches  for  the  purpose  of  digging  out  the  larva?.  Plate  VIII. 
tig-.  1.  2,  •">.  -how-  stubs  <>f  branches  from  an  old  orchard  near  Elkton. 
Aid.,  in  which  these  birds  have  done  efficient  work  in  reducing  the 
number  of  larvae  during  the  spring.  Fig.  2  is  especially  interesting. 
as  on  close  examination  it  shows  the  following  points:  Some  time  in 
.  in  the  course  of  pruning  the  orchard  a  branch  was  cut  away, 
leaving  the  -tub.  which  is  8  inches  long.     In  the  following  winter  and 


58 

Spring  the  stub  began  t<>  crack  and  decay  and  the  bark  (o  loosen. 
Many  codling-moth  larvae  crawled  under  the  bark  in  the  fall  of  L901. 
The  woodpeckers  found  this  stub  in  the  following  winter  and  spring, 
and  not  only  probably  secured  all  the  lame  which  were  under  the 
bark,  but  enlarged  one  of  the  main  cracks  in  order  to  get  those  which 
were  hidden  inside.  In  (he  fall  of  L902  all  the  hark  had  fallen  from 
this  stub  and  many  more  lame  took  refuge  in  the  cracks.  Upon 
examination,  in  May.  L903,  the  writer  found  that  the  crack  had  been 
recently  enlarged,  as  is  well  shown  in  the  reproduction.  This  recent 
enlarging  was  probably  done  mostly  by  the  pileated  woodpecker 
(Oeaphehts  pileatus)^  as  the  chips  broken  out  were  quite  large,  and 
probably  required  more  strength  than  other  smaller  woodpeckers 
could  muster.  This  stub  was  sawed  from  the  tree  and  sent  to  the 
writer,  and  in  the  latter  part  of  May  the  moths  emerged,  and  28  empty 
pupal  skins  were  found  on  June  25.  The  writer  estimates  that  fully 
100  larvae  hibernated  in  this  stub. 

It  is  highly  probable  that  all  woodpeckers  feed  on  the  codling  moth 
larva).  Other  birds,  including  the  nuthatches,  black-capped  titmice, 
wrens,  bluebirds,  crows,  blackbirds,  kingbirds,  swallows,  sparrows, 
chickadees,  and  jays,  may  also  feed  upon  the  codling  moth,  especially 
those  birds  which  winter  in  the  locality  where  the  larva?  are  present. 
Without  doubt  the  bobwhite  quail,  which  has  been  introduced  into 
many  sections  of  the  West,  also  feeds  upon  this  insect.  At  best  our 
knowledge  of  the  food  habits  of  many  of  these  birds  in  regard  to  the 
codling  moth  is  based  upon  but  little  direct  evidence;  but  reasoning 
from  what  we  do  know  positively,  there  is  little  doubt  that  codling 
moths  form  a  part  of  the  diet  of  at  least  some  of  these  birds.  Not 
many  years  ago  a  movement  was  set  on  foot  in  the  Pacilic  northwest 
to  import  the  German  kohlmeisen  into  this  country,  as  it  was  said  to 
feed  hugely  upon  the  larvae  of  the  codling  moth;  but  because  the  bene- 
fit s  derived  from  the  bird  in  its  native  home  were  not  clearly  proven, 
and  that  it  sometimes  injured  fruit,  and  also  on  account  of  many  dis- 
astrous experiences  in  the  importation  of  birds  and  mammals  which 
have  already  been  made,  the  majority  of  the  authorities  were  con- 
vinced  that  it  would  be  a  dangerous  experiment,  and  no  further  action 
was  taken.  Th<'  expenditure  of  time  and  money  necessary  to  carry 
out  such  a  project  would  probably  be  more  beneficial  if  applied  to  the 
protection  of  our  native  birds. 

Koebele  writes  that  in  California  he  knows  of  many  small  bats  Hy- 
ing around  the  apple  trees  in  the  evening,  taking  moths  on  the  wing, 
and  even  darting  down  to  take  moths  which  were  upon  the  leaves.  The 
writei-  has  often  noticed  bats  Hying  about  the  apple  trees,  but  was 
unable  to  obtain  any  evidence  that  they  were  catching  codling  moths. 


59 

INVERTEBRATE  ENEMIES. 

The  writer  has  often  found  moths  in  limb  cages  dead  with  spider's 
silk  wound  around  them,  but  made  no  further  observations.  The 
insect  enemies  of  the  codling  moth  are  either  predaceous  or  parasitic, 
and  are  quite  numerous  as  to  species,  but  are  usually  few  as  to  individ- 
uals. A  large  number  of  predaceous  insects  in  the  larval  stage  have 
been  observed  feeding  upon  the  codling  moth,  the  following  list  being 
compiled  from  publications  of  various  authors: 

Cltauliognathus  pennsylvanicus.  Pterostirh us  California's. 

Chauliognathus  marginatus.  CalaLhius  rufipes. 

Telephorus  bilineatus.  Dermestid. 

Trogosita  corticalis.  Clerid. 

Trogosita  laiicoHis.  Chrysopa. 

Trogoderma  tarsalis.  Raphidid. 
1',  rimegatoma  rariegata. 

In  regard  to  many  of  these  predaceous  insects  it  is  doubtful  whether 
they  feed  upon  the  living  codling  moth  larva  or  upon  dead  specimens. 
At  best,  they  do  not  reduce  the  number  of  the  larvae  to  any  consider- 
able extent.  In  Utah  a  species  of  Ammophila  was  found  stocking  its 
burrows  with  larva?  of  the  codling  moth.  It  is  also  recorded  in  Cali- 
fornia that  8j>hedus  nevadensis  was  found  pulling  the  larvae  out  of 
their  burrows. 

Many  observers  have  found  the  eggs  parasitized  by  a  species  of 
Trichogramma.  Even  in  its  protected  life  the  larva  is  preyed  upon 
by  many  parasitic  insects,  among  which  are  the  following: 

Goniozus  sp.  P'unpla  annvMpes. 

Macrocentrus  delicatus.  Bethylus  sp. 

The  writer  found  traces  of  three  species  of  parasitic  Hymenoptera 
which  were  preying  upon  the  codling  moth  in  the  Pacific  northwest,  but 
was  unable  to  breed  any  of  them.  Among  the  Diptera  only  one  para- 
site is  mentioned,  namely,  Hyp<>xt<n<i  variabilis. 

In  general  it  may  be  said  that  these  parasitic  insects  are  found  in 
such  numbers  to  be  of  value  only  in  neglected  orchards,  and  in  any 
orchard  that  is  well  taken  care  of,  sprayed,  banded,  and  otherwise 
treated  in  preventive  and  remedial  ways,  these  predaceous  and  para- 
sitic insects  are  found  in  very  small  numbers  or  are  entirely  absent. 

Even  with  the  host  of  enemies  arrayed  against  it,  the  codling  moth 
under  normal  conditions  in  the  West  will  ruin  practically  all  of  the 
apple  crop,  and  if  success  is  to  be  obtained  proper  measures  of  con- 
trol b}*  human  agencies  must  be  instituted,  and  the  parasitic  and  pre- 
daceous enemies  left  out  of  the  question,  except  woodpeckers,  which 
may  be  encouraged  with  profit. 


60 

HOW  TO  COMBAT  THE  INSECT. 

The  codling  moth  seems  to  have  been  present  and  injurious  in 
orchards  for  centuries,  but  until  aboul  eighty  years  ago  no  one  seems 
to  have  made  any  suggestions  as  to  how  its  ravages  might  be  cheeked. 
It  would  require  volumes  to  contain  all  that  lias  been  written  aboutthe 
methodswhich  have  been  used  against  this  insect  most  of  them  value- 
less. Before  considering  methods  of  combating  the  insect  there  are 
several  points  which  must  he  discussed. 

Many  of  the  Western  States  have  horticultural  laws  which  aim  at 
extermination,  and  many  of  the  corps  of  inspectors  are  working  with 
that  end  in  view;  others,  however,  from  recent  experience  have  been 
led  to  change  their  views  upon  tin4  subject.  When  one  discusses  the 
extermination  of  an  insect  he  ventures  upon  debatable  ground.  As  yet 
no  insect  has  been  exterminated  through  the  agency  of  man,  and  judg- 
ing from  past  experiences  the  writer  believes  that  it  is  impossible  to 
exterminate  the  codling  moth  even  in  a  single  orchard.  The  control  of 
it.  by  means  by  which  the  damage  it  inflicts  is  reduced  to  a  minimum. 
i>  the  very  hot  thai  we  can  expect  to  accomplish.  It  is  a  prime  neces- 
sity, in  order  to  make  recommendations  of  value,  that  the  entomologist 
have  an  accurate  knowledge  of  the  life  history  of  an  insect.  Not  only 
is  this  necessary  for  the  entomologist,  hut  it  is  essential  for  the  fruit 
grower  also  to  understand  it.  in  order  that  he  may  apply  recommen- 
dations intelligently  and  vary  them  to  suit  conditions.  The  erroneous 
ideas  some  fruit  growers  have  upon  the  life  history  of  the  codling  moth 
are  sometimes  startling,  following  recommendations  simply  because 
they  are  given  to  them,  and  having  no  idea  of  the  reason  therefor. 
Often  they  obtain  o-ood  results,  but  more  often  failures  result;  and  as 
they  do  not  understand  the  reasons  for  the  recommendations,  they  are 
at  a  loss  to  know  why  they  did  not  obtain  good  results.  To  combat 
the  insect  successfully  the  fruit  grower  must  be  familiar  with  all  the 
stages  of  the  insect,  the  sequence  of  the  stages,  where  found,  and  hab- 
its and  variations.  lie  should  also  be  informed  how  the  preventive  and 
remedial  measures  act  in  reducing  the  numbers  of  the  insects.  With 
this  knowledge  he  will  be  able  to  vary  the  recommended  preventive  or 
remedial  measures  to  exactly  lit  his  local  conditions,  and  if  any  failures 
OCCUr  he  will  in  a  measure  be  able  to  tell  why  they  occur,  and  the  fol- 
lowing year  the  experience  will  aid  him  in  changing  his  methods  in 
order  to  obtain  better  results.  He  will  also  be  protected  against 
using  methods  which  are  of  no  value,  and  will  thus  avoid  a  Large 
unnecessary  expense. 

PREVENTIVE  MEASURES. 

Preventive  measures  are  those  which  not  only  aid  in  controlling  the 
codling  moth,  but  aid  the  fruit  grower  in  training  trees  so  as  to  bear 

more    fruit,  support    it  while  growing,  and  produce    fruit    of  a   better 


61 

quality,  size,  and  color.  Although  many  of  these  questions  are  not 
closely  allied  to  the  control  of  the  codling  moth,  they  are  of  impor- 
tance, as  anything  which  increases  the  margin  of  profit  aids  in  secur- 
ing better  general  results  from  an  orchard. 

There  are  many  methods  of  prevention  which  ma}'  he  applied  to 
keeping  the  insect  out  of  a  section  of  the  country  in  which  it  is  not 
vet  present.  By  study  of  the  means  of  its  spread  it  will  he  learned 
how  it  may  have  entered  the  country,  and  by  closing  all  possible  ave- 
nues of  introduction  immunity  may  be  secured  for  many  years:  but 
if  fruit  is  being  continually  shipped  into  a  new  country  from  an 
infested  district,  it  is  only  a  question  of  a  few  years  when  in  spite  of 
all  that  can  be  done  the  insect  will  gain  a  foothold.  Whether  it 
becomes  injurious  or  the  loss  is  nominal  will  depend  upon  many  condi- 
tions. 

Many  orchardists  who  have  planted  young  orchards  in  infested 
districts  are  quite  desirous  of  keeping  the  codling  moth  out  of  their 
orchards  as  long  as  possible,  but  if  there  are  infested  orchards  near  by 
this  is  a  practical  impossibility.  It  may  be  said  that  money  and  labor 
spent  in  keeping  the  insect  out  of  a  section  or  an  orchard  will  accom- 
plish more  good  if  directed  toward  the  stud}'  of  better  orchard  methods 
and  adapting  the  measures  of  control  to  that  section  of  the  country. 

To  insure  the  best  results  in  the  planting  of  a  young  orchard  in  an 
infested  locality  the  codling  moth  should  be  considered  from  the  very 
first,  and  everything  that  is  done  should  be  done  only  after  taking  into 
account  the  actual  or  probable  presence  of  the  insect.  If  note  is  taken 
of  these  methods  and  they  are  faithfully  carried  out,  a  great  amount 
of  labor  and  loss  will  be  saved  when  the  orchard  is  in  bearing.  There 
are  many  questions  which  can  be  decided  for  each  locality  only  after 
all  the  conditions  over  which  the  fruit  grower  has  no  control,  such  as 
transportation,  exposure,  temperature  limits,  and  proximity  to  water, 
have  been  fully  considered.  Although  the  question  of  soils  is  very 
important,  by  appropriate  methods  the  character  of  some  soils  can  be 
materially  changed,  as  by  cultivation,  cover  crops,  and  other  means. 
The  first  question  which  confronts  a  man  wishing  to  plant  an  orchard 
is  the  question  of  varieties,  which  is  one  of  the  most  difficult  problems 
to  be  solved.  The  soil,  the  climate,  the  purpose  for  which  apples 
are  grown,  and  various  other  factors,  must  be  considered,  each  one 
having  its  own  bearing  upon  the  problem.  If  a  home  orchard,  the 
likes  and  dislikes  of  the  grower  are  the  first  consideration,  but  if  the 
aim  is  to  plant  and  maintain  a  commercial  orchard,  the  question  of 
varieties  must  be  determined,  first,  by  finding  what  varieties  are  well 
adapted  to  the  locality  in  question.  This  can  be  learned  by  consulting 
the  experiment  station  officials  in  the  different  States  and  from  the 
experience  of  growers  who  have  orchards  in  that  locality.  The  next 
consideration  is  what  varieties  will  meet  the  market  demands  and  com- 


62 

mand  the  highest  prices.  It  is  ;i  well-known  facl  that  in  the  arid 
regions  of  the  Pacific  Northwest  the  Jonathan.  Grimes  Golden,  Komc 
Beauty,  BeD  Davis,  Winesap,  and  a  few  others  are  the  best  adapted 
to  a  commercial  orchard;  while  in  the  humid  sections  of  the  same 
region  the  Newtown  Pippin.  Spitzenberg,  and  a  few  others  have  proven 
most  successful.      It  might    he  well    to   note    here,  as   has   been   stated 

before,  that  the  Pewaukeeand  Ortley  apples  are  always  found  worst 
infested  with  the  codling  moth,  while  the  Lawyer  and  Winesap  are 
least  infested. 

After  it  has  been  decided  which  varieties  to  plant,  the  next  question 
is  that  of  buying  the  stock.  Good  stock  should  always  be  insisted 
upon,  and  one  can  be  sure  of  securing  the  desired  varieties  only 
by  buying  from  well-established,  conscientious  nurserymen.  It  is 
preferable  in  the  arid  region  of  the  Northwest  to  plant  1-year-old 
stock.  The  land  usually  has  some  vegetation  upon  it,  such  as  sage 
brush  or  timber,  and  after  clearing  it  the  soil  should  be  thoroughly 
pulverized.  If  irrigation  is  intended,  the  ground  should  be  leveled 
and  graded  to  facilitate  irrigation.  The  courses  of  the  irrigation 
ditches  should  be  determined  by  the  general  contour  of  the  land,  tak- 
ing into  consideration  the  future1  routes  of  the  spraying  machine,  which 
will  draw  upon  these  ditches  for  water  for  spra}Ting. 

SETTING    THE    TREES. 

There  are  many  methods  which  may  be  used  for  setting  the  trees, 
the  details  depending  on  the  size  of  the  orchard  and  the  means  at  hand. 
The  essential  feature  of  the  operation  is  to  make  the  holes  large 
enough  to  receive  the  roots  of  the  tree,  so  that  they  can  still  retain 
their  natural  position.  After  tilling  and  packing  earth  into  the  holes, 
water  should  be  allowed  to  run  in,  to  aid  in  giving  the  trees  a  good 
start. 

It  has  been  found  that  it  is  a  very  injurious  practice  to  place  any 
manure  in  the  holes  when  the  tree  is  planted.  If  manure  is  to  be 
applied  in  the  new  orchard,  the  best  method  is  to  scatter  it  over  the 
surface  of  the  ground. 

(are  should  be  taken  to  Cause  the  trees  to  lean  toward  the  south- 
west, from  which  the  hottest  pays  of  the  sun  come.  By  doing  so.  sun 
scald  will  in  a  great  measure  be  avoided.  After  sun  scald  the  bark 
breaks,  and  the  wood  is  exposed  and  becomes  cracked  and  decayed. 
It  has  often  been  found  that  trees  thus  affected  always  bear  a  larger 

percentage  of  wormy  apples  than  trees  on  which  the  bark  is  unbroken. 
This  is  accounted  for  by  the  fact  that  the  codling  moth  larva*  go 
into  the  cracks  to  spin   their  cocoons  and  are  there  secure  from  their 

enemies. 

It  is  a  common  sight  in  all  sections  of  the  country  to  see  trees 
planted    from    L6   to   18   feet  apart,  with  the  upper  branches  intermin- 


63 

gling  .so  as  to  form  a  dense  mass  of  branches  which  can  not  be  sprayed 
properly,  and  there  is  no  room  between  the  rows  for  wagons  or  culti- 
vators. It  is  strongly  urged  that  the  trees  be  set  not  closer  than  30 
feet  apart;  some  growers  prefer  10  feet. 

PRUNING. 

No  arbitrary  rules  can  be  made  for  pruning  on  account  of  the  fact 
that  every  kind  of  tree  and  plant,  in  fact  every  individual,  presents 
its  own  peculiar  problem;  but  there  is  an  ideal  which  the  pruner  should 
endeavor  to  attain.  It  is  found  in  many  sections  of  the  West  that  the 
trees  have  been  allowed  to  fork  so  that  there  are  two  or  three  main 
branches,  and  upon  bearing  a  heavy  crop  these  branches  have  split 
apart,  sometimes  totally  ruining  the  tree.  At  best,  if  the  branches 
are  brought  back  into  place  and  held  by  bolts,  wires,  or  ropes,  a  crack 
will  be  left,  into  which  fungous  diseases  can  enter  and  in  which  codling 
moth  larvae  will  spin  their  cocoons.  Such  a  break  should  be  dressed 
with  grafting  wax  or  shellac  varnish,  and  the  branches  fastened  closely 
together.  With  proper  pruning,  when  the  head  of  the  tree  is  being 
formed,  this  trouble  may  be  avoided.  Instead  of  two  or  three  main 
branches,  the  head  of  the  tree  should  be  so  formed  as  to  have  four  to 
six,  thus  distributing  the  weight,  and  preventing  breakage  under 
ordinary  conditions. 

Many  apple  growers  have  headed  their  trees  too  high  for  best 
results.  The  disadvantages  of  this  method  are  that  it  is  difficult  to 
reach  the  fruit  and  foliage  with  spray,  and  much  more  difficult  and 
expensive  to  harvest  the  fruit.  Other  growers  have  headed  their  trees 
so  low  that  the  branches  spread  and  droop  so  that  they  are  close  to  the 
ground.  In  many  instances  when  there  is  a  heavy  crop  of  fruit  these 
branches  bend  down  and  either  touch  or  lie  upon  the  ground.  The 
result  is  that  much  of  the  fruit  on  the  interior  of  these  trees  and  on 
the  under  sides  of  the  outer  branches  is  so  shaded  by  the  foliage  that 
the  sunlight  can  not  reach  it,  and  a  large  percentage  will  be  poorly 
colored  and  of  second  quality.     (See  PI.  IX.) 

A  mean  between  this  high  and  low  heading  is  to  be  desired,  which 
will  do  away  with  most  of  the  disadvantages  of  these  extreme  methods. 
In  order  to  secure  proper  coloring  in  fruits  on  trees  it  is  necessary 
that  enough  smaller  branches  be  removed  to  admit  an  abundance  of 
sunlight  through  the  tops. 

In  the  arid  sections  of  the  Far  West  the  trees  grow  with  great  rapid- 
ity, and  if  allowed  to  take  their  natural  course  become  slender  and  not 
strong  enough  to  support  a  normal  weight  of  fruit.  It  has  been  found 
that  by  cutting  back  half  of  each  year's  growth  the  trees  will  be  made 
to  grow  heavier  and  stockier,  and  thus  be  able  to  support  the  weight 
of  a  large  load  of  fruit  without  any  danger  of  breaking. 


<u 


[RRIGATION. 


Proper  irrigation  of  the  orchard  depends  entirely  upon  the  condi- 
tions.    There  are  several  methods  of  employing  water  in  irrigation 

by  flooding,  by  a  system  of  check-,  or  by  furrows.  The  latter  is 
probably  the  most  efficient,  but  care  should  be  taken  that  both  side-  of 

the  tree  receive  an  equal  supply  of  water. 

soil.   OB   COVEB   CROPS. 

The  soil  of  different  localities  varies,  and  the  treatment  should  van 
with  the  conditions.  In  irrigated  sections  the  soil  is  usually  lacking 
in  humus,  and  is  often  packed  so  closely  together  that  it  i-  impervious 
to  water.  By  proper  tillage  this  is  corrected  to  some  extent,  hut  the 
greatest  success  has  been  attained  by  growing  cover  crops.  Red  clover 
i-  successfully  used  for  this  purpose,  and  is  advantageous  in  many 
way-.  The  root-  penetrate  deeply  into  the  soil,  thus  forming  passi 
for  water:  by  keeping  a  cover  of  clover  over  the  soil,  evaporation  from 
the  -oil  is  retarded,  and  the  irrigation  need  not  he  so  frequent,  as  the 
water  i-  retained  for  a  longer  time;  the  clover  can  he  cut  and  used  for 
hay:  and  about  every  third  year  the  practice  of  plowing  the  clover  is 
followed,  so  that,  in  addition  to  the  fixing  of  nitrogen  by  the  root-  of 
the  clover,  the  decaying  vegetation  add-  needed  humus  to  the  soil. 

ORCHARD    IN    BEAK  INC 

A  very  serious  error  is  made  by  many  fruit  growers  in  regard  to 

the  first  crop  of  fruit.  Reasoning  that  the  first  crop  is  not  worth 
trying  to  save  from  the  codling  moth,  the  grower  allows  the  insect  to 
infest  most  of  it.  intending  the  following  year  to  apply  preventive 
and  remedial  measures  and  put  it  under  control.  The  result  usually 
i-  that  the  following  year  he  has  an  abundance  of  insects,  and  his  loss 
will  be  considerable.  Jf.  when  the  larvae  were  all  in  this  first  crop,  the 
apple-  had  been  destroyed  by  being  picked  and  buried,  or  if  bands 
had  been  used  late  in  the  summer,  a  large  percentage  of  the  Loss  in 
the  second  year  could  have  been  prevented. 

It  i-  often  the  case  that  on  account  of  some  unforeseen  condition. 
such  a-  a  freeze  ora  frost,  the  fruit  crop  is  reduced  to  almost  nothing. 
Under  such  condition-  each  grower  must  decide  for  himself  what 
methods  he  will  pursue.  Usually  in  such  years  the  price  of  fruit  is 
very  high,  tempting  the  grower  to  produce  all  the  fruit  he  can.  even 
if  infested.  The  writer  recommends  that  when  the  crop  i-  80  -mall 
that  each  tree  will  produce  only  about  one  box  or  les-  of  good  fruit. 
the  fruit  should  be  picked  and  destroyed,  not  earlier  than  the  middle 
of  July  nor  later  than    the  middle  of    Augu-t.  and  other  method-  -uch 

a-  banding  should  be  used  to  destroy  as  many  of  the  remaining  insects 
a-  possible.  Various  instances  have  been  under  the  observation  of  the 
writer  in  which  these  suggestions  were  followed  with  great  Buccess. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  VIII. 


Fig.  1.  Fig.  2. 

Stubs  of  Branch  Cut  from  a  Tree,  Showing  Work  of  Woodpecker. 


Fig.  3.— Stub  about  8  Inches  Long,  Showing  Work  of  Codling  Moth 
Larv/e  and  Woodpecker. 

Twenty-eight  moths  which  the  woodpeckers  did  not  get  emerged  from  this  piece  of  wood. 

STUBS    OF    BRANCHES    FROM    AN     OLD    ORCHARD    NEAR 
ELKTON,    MD. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  IX. 


65 

There  are  many  preventive  measures  which  may  be  applied  to  the 

orchard  when  it  is  in  bearing. 

It  is  a  well-known  fact  that  an  orchard  which  produces  a  moderate 
crop  each  year  is  much  more  profitable  than  one  which  produce-  an 
abnormally  large  crop  one  season  and  a  very  small  one  the  next.  By 
thinning  each  year  this  alternation  may  be  prevented  to  some  extent. 

The  writer  is  very  strongly  of  the  opinion  that  if  thinning  1-  done 
when  the  larvae  of  the  first  generation  are  in  the  fruit,  and  the  fruit 
and  larvae  destroyed,  the  advantages  thereby  gained  are  sufficient  to 
compensate  for  the  expense  of  thinning. 

It  is  easy  to  see  how  the  destruction  of  part  of  the  first  generation 
will  prevent  much  of  the  injury  due  to  the  second  generation,  which  is 
about  ten  times  that  by  the  first  generation.  It  is  difficult  for  the 
orchardist  to  determine  by  observing  the  entrance  holes  about  what 
time  the  insects  are  inside  the  fruit.  In  thinning,  all  terminal  clusters 
should  be  reduced  to  one  fruit,  and  none  should  be  allowed  to  grow 
closer  together  than  from  4  to  0  inches.  During  the  process  of  thin- 
ning, with  but  little  increased  expenditure  of  time  or  money,  the 
wormy  fruits  can  be  removed  and  the  perfect  left  on  the  tree. 

Throughout  the  season  a  large  number  of  fruits  will  drop  from  the 
tree  to  the  ground.  Upon  examination  it  will  be  found  that  under 
normal  conditions  the  larger  percentage  of  these  are  the  result  of  the 
work  of  the  codling  moth.  The  percentage  varies,  however,  with 
many  conditions.  If  a  tree  is  heavily  loaded,  a  large  number  of  good 
fruits  will  be  pushed  off  by  those  adjoining,  and  the  wind  will  cause 
many  to  fall.  The  quantity  of  windfalls  increases  throughout  the 
season. 

The  percentage  of  the  larvae  to  be  found  inside  the  wormy  fruit 
varies  with  the  time  of  the  year.  In  the  Pacific  Northwest  the 
latter  part  of  June  and  the  first  part  of  July  and  the  latter  part  of 
August  are  the  times  when  the  largest  number  of  larva*  are  found 
inside  the  wormy  windfalls.  In  a  small  orchard  these  windfalls  can 
be  destroyed  by  allowing  hogs  to  run  at  large  in  the  orchard  and  eat 
the  fallen  apples:  or  the  windfalls  may  be  picked  up  every  few  days 
and  either  made  into  cider  or  destroyed.  In  a  large  commercial 
orchard,  however,  it  is  not  probable  that  the  expense  of  keeping  the 
ground  clear  of  windfalls  would  be: justified  by  the  benefits  derived, 
although  such  benefits  would  undoubtedly  be  great. 

PREPARING    FRUIT    FOR    THE    MARKET. 

The  method  of  packing  which  is  now  coming  into  use  is  to  pack  the 
fruit  in  the  orchard,  using  packing  tables  built  upon  runners.  These 
are  hauled  down  a  row.  stopping  at  intervals.  Two  rows  are  picked 
on  either  side  of  the  table,  and  the  fruit  is  carried  from  the  trees  to 
the  tables  by  the  pickers.  The  fruit  is  there  graded  and  packed,  and 
6514^-No.  41— 03 5 


66 

ilif  culls  arc  left  in  piles  in  the  orchard.  The  advantages  of  this 
method  of  packing  arc  many.  The  fruit  is  bandied  but  once,  and 
ifi  not  hauled  any  distance  until  it  has  been  securely  packed,  and  the 
danger  of  breaking  the  skin  or  bruising  is  reduced  to  a  minimum. 
The  picking  and  packing  crews  also  work  as  smaller  units,  and  can  he 
more  easilj  directed  and  do  far  better  work.  The  codling  moth  larva' 
in  the  culls,  after  completing  their  development,  will,  if  allowed  to  do 
so,  spin  their  cocoons  among  the  apples  in  the  piles.     (See  PL  XVI.) 

Fruit  may  l>e  well  grown,  well  colored,  and  of  proper  varieties,  hut 
if  not  well  packed  these  conditions  are  nullified.  Apple  growers  in 
the  Far  West  are  confronted  with  rather  special  problems.  By  reason 
of  their  distance  from  the  large  markets  of  the  United  States,  the 
price  they  would  receive  for  second-quality  fruit  would  hardly  he 
sufficient  to  pay  the  expense  of  growing,  packing,  and  shipping,  and  it 
is  incumbent  upon  them  to  ship  nothing  except  that  which  is  Btrictly 
first  class,  packed  in  strictly  first-class  manner.  The  cost  of  transpor- 
tation, prevailing  market  price,  and  size  of  crop,  however,  must  he 
taken  into  consideration. 

The  methods  of  packing  depend  upon  the  kind  of  package  used. 
Fa-tern  grown  apples  are  usually  packed  in  barrels.  From  Colorado 
and  Montana  westward  boxes  containing  either  4<>  or  50  pounds  are 
almost  universally  used.  Some  are  even  going  further,  using  small 
packages  containing  half  bushels  of  superior  fruit.  There  are  many 
methods  of  packing  the  fruit  in  these  boxes,  as  may  he  required  by 
the  purchasing  dealers.  In  all  cases  it  is  highly  essential  that  the  fruit 
he  packed  SO  tightly  in  the  box  that  there  can  he  no  shifting  of  posi- 
tion while  in  transit;  that  there  he  a  decided  swell  in  the  boxes  on  both 
top  and  bottom  if  they  are  made  of  thin  and  flexible  wood,  as  is 
usually  the  case  in  the  West;  that  the  paper  lining  of  the  box  remain 
unbroken,  and  that  when  the  fruit  is  opened  it  will  be  attractive  to 
the  buyer. 

The  more  progressive  fruit  grower  is  well  aware  of  the  fact  that 
a  reputation  for  first-class  fruit  can  be  obtained  and  secured  only 
by  packing  such  fruit  and  rigorously  excluding  all  wormy  or  scale- 
infested  apples.  Although  it  is  extremely  difficult  for  a  packer  to 
put  up  a  hox  of  apples  containing  not  a  single  wormy  fruit,  it  should 
he  firmly  impressed  upon  his  mind  that  is  the  ideal  to  be  attained,. 

The  second-quality  apples,  which  are  usually  disposed  of  in  the 
local  market-,  are  those  but  slightly  injured  by  the  codling  moth,  or 
undersized  or  uncolored.  The  culls  and  windfalls  should  be  piled 
together  and  disposed  of  as  quickly  a-  possible.  They  may  be  either 
fed  t<>  stock  immediately  or  made  into  cider  for  vinegar.  The  value 
of  these  culls  is  considerable,  and  progressive  orchardists  count  a 
good  deal  on  the  revenue  derived  from  them.  From  the  seconds, 
culls,  and  windfall-   in   one  orchard  with  which   the  writer  is  familiar 


67 

5,000  gallons  of  cider  were  made,  which  sold  for  as  high  as  20  cents 
per  gallon.  One  bushel  of  apples  made  from  2J  to  3i  gallons  of 
cider,  by  means  of  a  hydraulic  press  run  by  the  gasoline  engine  used 
in  spraying. 

If  it  is  not  possible  to  dispose  of  the  culls  otherwise,  they  should 
be  buried  in  holes  in  the  orchard  and  covered  over  with  6  to  8  inches 
of  closely  packed  earth.  (PL  VI.  fig.  2.)  Occasions  may  arise  when 
it  is  necessary  to  store  these  for  some  time,  although  the  storing  of 
such  fruit  should  be  avoided  if  possible. 

Fruit  should  be  stored  in  a  house  in  which  there  are  no  holes  or 
cracks  in  the  roof  or  walls.  When  the  larvae  inside  the  fruit  have 
completed  their  development  they  spin  cocoons  and  transform  into 
pupa?,  which  in  turn  transform  into  moths.  These  moths  emerge, 
and  if  there  are  cracks  or  holes  in  the  house  they  will  escape  and  fly 
to  the  orchard  the  following  spring.  If,-  however,  the  house  is  tight 
it  may  be  fumigated;  or,  better  still,  screens  may  be  placed  over  the 
windows,  and  as  the  moths  collect  upon  these  screens,  they  may  be 
crushed,  or  they  will  die  if  left  a  week  or  so. 

The  writer  studied  two  cases  in  Idaho  in  which  apples  were  stored 
quite  near  an  orchard.  (PI.  IV.  tigs.  2  and  3.)  The  effect  was  that 
the  following  year  the  part  of  the  orchard  nearest  the  apple  house 
was  always  most  infested,  and  in  spite  of  all  the  remedial  measures 
applied  there  was  a  great  amount  of  damage.  In  California  it  was 
found  by  Mr.  De  Long  that  in  a  house  in  which  apples  were  stored 
the  moths  always  emerged  and  went  to  the  windows.  Eecords  were 
kept  of  these  insects,  and  it  was  found  that  11,974  moths  were  killed 
from  April  15  to  August  12.  One  can  easily  imagine  what  destruc- 
tion these  moths  would  have  caused  had  they  been  allowed  to  fly  to 
the  orchard. 

PREVENTIVE  MEASURES  IX  OLD  ORCHARDS. 

In  all  sections  of  the  country  old  neglected  orchards  are  easily  found 
in  which  practically  all  of  the  fruit  is  infested  by  the  codling  moth. 
The  writer  is  quite  familiar  with  two  typical  orchards,  one  of  which  is 
situated  in  an  irrigated  section  of  the  far  West  and  the  other  in  a 
humid  section  of  the  East.  Although  the  climatic  and  other  conditions 
are  quite  different  the  two  orchards  have  many  features  in  common. 

The  western  orchard  consists  of  about  300  trees  about  18  or  20 
years  old.  planted  about  16  feet  apart  each  way.  The  branches  of 
each  tree  touch  those  of  the  surrounding  trees  so  as  to  form  a  dense 
mass  of  branches  and  foliage.  Theformer  owner  of  the  orchard,  find- 
ing that  the  codling  moth  destroyed  the  larger  part  of  the  fruit,  gave 
the  orchard  no  irrigation,  and  in  consequence  the  trees  are  in  a  more 
or  less  stunted  condition.  The  branches  are  thickly  matted  together, 
having  never  been  pruned.     The  trunks  and  branches  of  the  trees  are 


68 

covered  with  rough  scales  of  bark,  and  where  branches  have  been  cut 
away  the  stubs  remain,  with  irregular  cut  ends,  the  branches  hav- 
ing been  hacked  off  with  an  ax.  These  stubs  have  in  many-  places 
cracked  and  begun  to  decay,  thus  making  excellent  places  in  which  the 
larvae  of  the  codling  moth  could  spin  their  cocoons  and  hibernate. 
The  writer  once  secured  20  larvae  from  the  holes  and  cracks  in  one  of 
these  stubs.  The  cut  ends  were  not  given  proper  dressing  and  deca}T 
has  taken  place,  often  leaving  large  holes  in  the  trunks  and  branches. 
Many  cocoons  can  be  found  in  this  rotten  wood,  and  on  all  the  trunks 
and  branches  one  can  find  numerous  empty  pupal  skins  from  which 
moths  have  emerged.  The  soil  of  the  orchard  has  received  no  cultiva- 
tion and  is  covered  partly  with  weeds,  principally  prickly  lettuce. 
The  orchard  is  very  productive  and  always  bears  a  good  quantity  of 
fruit,  but,  being  undersized  and  from  90  to  98  per  cent  infested  by  the 
codling  moth,  practical^  no  revenue  has  been  derived  from  it  for  the 
past  live  or  six  years.  In  1900,  1901,  and  1902  the  writer  searched 
carefully  for  uninfested  fruit,  and  each  time  found  on  the  tree  near  the 
trunk  only  a  dozen  or  so  small  stunted  apples  which  had  escaped  the 
codling  moth.  Other  insect  pests  are  present  in  this  orchard,  each 
requiring  special  treatment. 

The  eastern  orchard  is  situated  in  a  good  horticultural  region.  The 
trees  number  about  300,  and  are  probably  about  twenty-five  years  old. 
They  are  placed  40  feet  apart,  and  have  made  a  good  growth.  The 
trees  have  received  some  pruning,  but  as  in  the  western  orchard  there 
are  many  stubs  left,  and  there  are  numerous  decayed  holes  in  the 
trunks  and  branches.  In  many  trees  the  branches  are  matted  together 
and  shade  the  fruit.  The  soil  is  in  fairly  good  condition  and  lightly 
sodded.  Until  the  past  two  or  three  years  the  orchard  has  been 
remarkable  for  its  productiveness,  but  a  large  percentage  of  the  fruit 
was  small  and  much  the  larger  part  of  it  was  infested  with  the  larvae 
of  the  codling  moth. 

The  treatment  that  these  orchards  should  receive  to  bring  the  cod- 
ling moth  under  control  is  about  the  same.  It  may  be  stated  that  if 
the  preventive  measures  advised  for  a  young  orchard  had  been  faith- 
fully and  intelligently  carried  out  man}^  of  the  existing  conditions 
would  not  have  been  present. 

TREATMENT  OF  OLD  ORCHARDS. 

The  first  thing  to  be  done  to  old  orchards  is  to  prune  the  trees  in 
such  a  manner  that  the  sunlight  and  spraying  solutions  will  have  easy 
access  to  the  foliage  and  fruit.  Every  other  tree  in  the  western 
orchard  should  be  cut  down.  The  stubs  of  branches  should  be  sawed 
off  close  to  the  trunks  and  burned  in  order  to  destroy  the  hibernating 
larvae  contained  in  them,  and  the  cut  ends  remaining  on  the  tree  cov- 
ered with  shellac  varnish  or  grafting  wax.     The  holes  in  the  trunks 


69 

and  branches  should  be  filled  with  cement,  plaster,  or  clay,  in  order 
that  the  insects  inside  may  be  confined  and  die,  and  that  other  larva* 
later  in  the  season  will  be  unable  to  enter  to  spin  their  cocoons.  The 
rough  bark  on  the  trunks  and  branches  should  be  scraped  away  and 
burned. 

In  both  of  these  orchards  it  is  a  noticeable  fact  that  the  woodpecker- 
have  been  very  efficient  in  digging  out  the  hibernating  larvae.  (PI. 
VIII.)  It  has  been  often  noted  by  authors  that  early  in  the  spring  it 
La  almost  impossible  to  find  larva*  of  the  codling  moth  under  the 
rough  bark  and  other  exposed  places  in  badly  infested  orchards. 
Instead  of  finding  the  cocoons  with  the  larva'  inside,  one  will  find 
empty  cocoons  with  a  hole  through  the  bark  of  the  tree,  showing  that 
the  insect  has  fallen  prey  to  woodpecker.-.  All  places  in  which  the 
larva*  might  spin  cocoons  should  be  destroyed  or  rendered  unsuitable, 
and  the  larva?  forced  to  spin  cocoons  in  exposed  places  where  the  wood- 
peckers and  other  birds  can  get  them. 

The  soil  in  these  two  orchards  should  receive  about  the  same  treat- 
ment, except  that  irrigation  should  be  begun  in  the  western  orchard. 
They  should  both  receive  a  very  shallow  cultivation  for  about  one 
year,  with  a  dressing  of  manure.  The  cultivation  should  be  so  -hal- 
low as  not  to  injure  any  of  the  roots,  which  may  be  quite  near  the 
surface.  The  second  year,  red  clover,  cowpeas.  or  some  other  legu- 
minous cover  crop  should  be  sown,  and  every  third  year  this  may  be 
turned  under,  thus  adding  available  plant  food  to  the  soil.  When 
these  methods  are  followed  the  recommendation  given  for  an  orchard  in 
bearing  should  be  adopted.  At  best  the  preventive  measures  can  not 
control  the  insect  in  an  orchard,  but  they  are  valuable  adjuncts  which 
render  the  measures  more  efficient. 

REMEDIAL  MEASURES. 

Remedial  measures  against  the  codling  moth  are  those  measures 
from  which  little  or  no  benefit  is  derived  except  in  saving  fruit  from 
the  ravages  of  the  insect  by  killing  it. 

MEASURES    ()F   LITTLE    OK    NO   VALUE. 

The  codling  moth  seems  to  have  been  common  in  orchards  for  many 
centuries,  but  no  one  made  any  suggestion-  a-  t<>  how  it-  ravages 
might  be  checked.  The  first  recommendations  made  were  of  no  value, 
and  it  is  interesting  to  note  how  the.-e  recommendations  have  recurred 
at  various  periods  in  popular  writing-.  Many  of  these  remedies, 
having  little  or  no  value,  are  taken  up  by  companies,  given  all  the 
benefit  of  modern  advertising  methods,  and  thoroughly  distributed 
before  the  fruit  growers  become  aware  of  their  worthlessness.  In 
order  that  the  fruit  grower  may  know  what  not  to  do  as  well  as  what  he 


To 

should  do,  a  Dumber  of  the  more  prominent  of  these  inefficient  methods 
arc  briefly  discussed. 

It  has  often  been  recommended  that  ninth  halls  be  hung  in  the  trees 
in  order  to  keep  the  moths  away.     If  there  were  any  virtue  in  this 

remedy,  SO  many  of  the  moth  halls  would  have  to  he  hung  on  each 
tree,  to  do  the  work,  that  the  expense  would  reader  it  valued 

Smudging  the  orchard,  or  burning  ill-smelling  compounds  so  that 
the  fumes  will  pass  through  the  tree-,  has  been  practiced  to  some 

extent.      The  theory  is  that  the  moths  will  he  kept  away  by  the  fumes 

and  go  to  other  orchards  to  deposit  their  eggs.  It  is  quite  evident 
that  as  soon  as  these  fumes  are  blown  out  of  the  orchard  the  moths 
will  return  if  they  have  left,  and  in  order  to  produce  any  results  it 
will  he  necessary  that  the  smudge  he  continued  practically  throughout 
the  season. 

Plugging  trees  with  sulphur  or  other  compounds  and  plugging  the 
roots  with  calomel  have  been  practiced  to  some  extent,  on  the  theory 
that  the  sulphur  or  calomel  will  he  taken  up  by  the  sap,  distributed 
through  the  tree,  and  prove  distasteful  or  poisonous  to  the  insect. 
Trustworthy  scientific  experiments  have  been  carried  on  which  show 
that  it  is  absolutely  impossible  for  the  tree  to  take  up  any  amount  of 
these  substances,  and  little  or  no  effect  upon  the  insects  results. 

The  writer  has  found  several  orchards  in  which  the  trees  were 
banded  with  tarred  paper,  the  evident  intention  being  to  keep  the  larvae 
from  getting  up  into  the  trees.  Knowing  the  habits  of  the  insect 
when  in  its  Larval  form,  we  can  see  that  this  method  is  ridiculous,  and 
instead  of  being  a  detriment  it  is  a  positive  aid  to  the  insect;  in  many 
cases  larva?  were  found  which  had  spun  cocoons  under  the  hands, 
which  formed  a  place  in  which  they  were  comparatively  free  from  the 
attacks  of  their  enemies. 

There  seems  to  he  a  popular  idea  among  many  farmers  and  fruit 
growers  that  all  insects  are  attracted  to  light.  Based  upon  this  idea, 
there  have  been  many  recommendations  to  keep  tires  burning  in  the 
orchards,  or  to  arrange  Borne  sort  of  a  trap  lantern  by  which  the  insects 
are  to  he  attracted  to  the  lights  and  fall  into  water  on  which  is  a  film 
of  kerosene  and  thus  he  killed.  This  scheme  of  trap  lanterns  was 
exploded  many  years  ago,  hut  it  seems  that  at  intervals  somebody 
revives  it.  and  its  fallacy  must  he  exposed  afresh.  By  carefully 
experimenting  with  trap  lanterns  and  determining  the  catch  as  accu- 
rately a-  possible  it  is  found  that  the  majority  of  the  insects  caught 
are  either  decidedly  beneficial  varieties,  or  are  males,  or  females  which 
have  already  deposited  their  eggs,  and  that  hut  few  injurious  insects 
aie  caught,  and  none  in  any  great  number.  Probably  the  most  exten- 
sive experiments  with  trap  lanterns  were  those  conducted  by  Professor 
Slingerland.  Among  i:'». <><><>  insects  he  was  not  able  to  recognize  a 
single  codling  moth.     This  is  the  usual  result  of  all  these  experiments, 


71 

and  we  can  say  without  any  hesitancy  whatever  that  the  fanner  who 
uses  these  trap  lanterns  or  tries  to  experiment  with  them  is  simply 
wasting  his  time  and  money,  as  the  method  has  been  thoroughly  proven 
ineffective. 

It  is  also  the  practice  to  some  extent  to  put  cans  or  bottles  contain- 
ing molasses,  cider,  vinegar,  or  some  other  substance  of  similar  nature 
in  the  orchard,  and  upon  finding  that  insects  are  attracted  by  these 
compounds  and  killed,  many  fruit  growers  think  this  is  a  good  remedy 
for  the  codling  moth.  The  results  of  many  careful  experiments  show 
that  only  incidental  captures  of  the  codling  moth  are  made.  With  both 
these  last  two  practices — that  is,  trap  lanterns  and  baiting  the  moths — 
the  greatest  trouble  has  been  that  the  fruit  growers  are  not  acquainted 
with  the  codling  moth  in  its  early  stages.  An}T  fruit  grower  can  breed 
moths  for  himself,  and  by  comparing  his  catch  can  very  easily  satisfy 
himself. 

Many  times  fruit  growers  have  tried  spraying  their  orchards  with 
ill-smelling  compounds  with  but  little  success.  These  compounds  are 
always  more  or  less  expensive  and  have  never  been  so  efficient  as  to 
justify  their  use. 

Other  fruit  growers  think  that  spraying  the  orchard  with  water 
frequently  will  give  relief  from  the  attacks  of  the  codling  moth. 
Undoubtedly  if  the  trees  were  kept  in  a  spray  all  the  time,  the  fruit 
would  be  clear  of  the  insect;  but  if  this  were  done,  the  probabilities 
are  that  no  fruit  would  set.  and  if  any  should  set  it  would  not  ripen 
well,  and  the  trees  themselves  would  probably  die.  The  expense  of 
this  operation  would  be  many  times  greater  than  that  of  spraying. 

It  has  been  stated  that  electric  lights  repel  the  moth  and  that  trees 
near  electric  lights  in  cities  are  often  free  from  its  work.  The  writer 
had  an  excellent  opportunity  to  investigate  this  point,  and  found  that 
an  apple  tree  about  4:0  feet  from  an  electric  light  was  as  badly  infested 
as  any  other  in  that  vicinity. 

In  order  to  do  away  with  the  labor  entailed  by  using  bands  around 
the  trees  man}T  kinds  of  traps  have  been  invented.  Riley,  by  careful 
experiments,  showed  that  one  of  these  traps  would  not  catch  as  many 
larvae  as  the  bands;  and  other  experiments  have  shown  that  these 
patent  traps  are  never  very  efficient. 

It  was  claimed  for  some  time  that  the  flowers  of  plants  of  the  genus 
Physianthus  might  be  efficient  against  this  insect,  since  in  order  to 
reach  the  honey  of  the  flower  the  proboscis  would  have  to  be  passed 
through  a  narrow  cleft,  from  which  it  could  not  be  withdrawn,  and 
the  moth  would  therefore  be  held  a  prisoner  until  it  died.  It  was 
proposed  to  train  the  vines  around  the  trunks  and  branches  of  the 
trees,  and,  the  moths  being  captured,  the  orchard  would  be  protected. 
Conclusive  evidence  has  been  recorded  which  .-hows  that  these  flowers 
have  no  attraction  for  the  codling  moth. 


It  has  been  suggested  thai  the  codling  moth  might  he  controlled  by 
bacteria]  and  fungous  diseases.  From  the  facts  thai  the  insect  leads 
such  a  protected  Life  and  that  fungi  and  bacteria  have  given  so 
few  positive  results  in  this  connection  it  is  almost  useless,  with  our 
present  knowledge,  to  even  theorize  upon  the  value  of  these  agencies. 

In  general  it  may  be  stated  that  entomologists  have  at  all  times 
tried  experiments  with  these  different  plans  and  are  unanimous  in 
their  conclusions.  If  anything  new  and  efficient  is  ever  perfected  by 
which  this  insect  may  be  more  easily  controlled,  no  doubt  entomolo- 
gists will  be  its  first  advocates. 

MEASUKES   OF    VALUE. 

By  taking  into  consideration  all  the  habits  and  variations  of  habits 
of  the  codling  moth  in  its  different  stages  we  find  that,  like  other 
insects,  there  are  certain  stages  in  its  life  history  in  which  it  is  more 
amenable  to  remedial  measures  than  at  others.  We  find  that  it  can  be 
best  attacked  in  the  larval  stage,  although  some  experiments  indicate 
that  something  can  be  done  when  it  is  in  the  egg  stage.  Cook  found 
that  by  spraying  an  apple  tree  weekly  from  May  L5  until  the  end  of 
June  with  a  strong  soap  solution  he  succeeded  in  preventing  the  infesta- 
tion of  a  single  apple  by  the  larvae.  In  laboratory  experiments  with 
kerosene  emulsion  Card  secured  good  results  against  the  eggs.  Gillette 
also  obtained  good  results  with  kerosene  emulsion.  The  results  of 
these  experiments  have  never  been  put  to  practical  use  for  many  rea- 
sons. The  kerosene  emulsion  would  probably  be  so  strong,  in  order 
to  have  any  effect  on  the  c<x<x,  that  it  might  injure  the  tree.  The 
kerosene  would  evaporate  quickly,  and  thus  its  effect  would  In4  for 
but  a  short  time.  The  expensiveness  of  kerosene  in  the  West,  and 
tin1  number  of  times  the  spraying  would  have  to  be  made  to  be 
efficient,  would  prohibit  the  adoption  of  this  method.  The  insect  can 
be  more  easily  attacked,  at  less  expense  and  with  greater  effectiveness, 
in  the  Larval  stage. 

MEASURES    USED    AGAINST   Tin:    LAIN  \. 

The  remedial  measures  used  against  the  larva  vary  according  to 
whether  they  are  used  after  it  has  been  hatched  and  before  or  while  it 
i-  entering  the  apple  or  after  it  has  completed  its  growth  and  left  the 
fruit.  The  greater  effectiveness  is  secured  by  the  use  of  arsenical 
sprays  before  the  larva  has  entered  the  fruit.  The  effectiveness  of 
these  arsenical  sprays  against  the  codling  moth  was  discovered  by 
accident  in  1^7iJ.  Le  Baron  recommended  the  spraying  of  trees  with 
Paris  given  to  check  the  ravages  of  the  canker  worm,  which  recom- 
mendation was  adopted  in  many  orchards  with  great  success.  Profes- 
sor Slingerland  states  that  the  credit  of  this  discovery  belongs  to  Mr. 
E.  P.  ELaynes  and  Mr.  J.  S.  Woodward,  who  found  that  spraying  with 


Paris  green  not  only  rid  the  orchard  of  cankerworms,  but  that  the 
apples  on  the  sprayed  part  were  much  less  affected  b}T  the  codling 
moth.  It  seems  that  other  people  used  Paris  green  for  cankerworms 
in  Iowa,  but  there  are  no  indications  that  they  were  alive  to  the  fact 
that  at  the  same  time  they  were  checking  the  codling  moth.  Prof. 
A.  J.  Cook,  of  Michigan,  took  up  the  idea  and  by  a  series  of  careful 
experiments  clearly  .showed  that  the  treatment  was  very  effective 
against  the  codling  moth.  Forbes,  Goff,  and  numerous  others  have 
at  various  times  carried  on  spraying  experiments  with  arsenicals,  with 
results  that  show  this  to  be  the  most  effective  and  cheapest  remedial 
measure  that  can  be  used. 


SPRAYING. 


Spraying  with  arsenicals  may  be  delined  as  putting  a  coat  of  any 
arsenical  poison  on  the  foliage  and  fruit  of  a  tree,  so  that  when  the 
insects  eat  the  foliage  or  enter  the  apples  they  eat  some  of  this  poison 
in  their  first  few  meals  and  are  killed.  Since  the  beginning  of  the 
practice  of  spraying  there  have  been  many  important  improvements 
in  both  spraying  machinery  and  spraying  solutions,  which  have  ren- 
dered the  process  much  easier  than  when  primitive  methods  were  in 
vogue. 


SPRAYING    MACHINERY, 


There  are  as  many  kinds  of  spraying  machinery  as  there  are  condi- 
tions to  be  met  in  spraying  operations.  There  are  certain  spraying 
outfits  devised  especiall}T  for  orchard  work,  varying  from  the  common 
bucket  pump  to  rather  complicated  machinery  driven  by  gasoline 
engines.  For  a  small  home  orchard  or  for  an  orchard  of  a  thousand 
trees  or  less  the  writer  would  advise  the  use  of  a  hand-power  outfit. 
The  capacity  and  cost  will  depend  primarily  upon  the  size  of  the 
orchard,  the  size  of  the  trees,  and  the  rapidity  with  which  it  is  desired 
to  spray  the  orchard.  There  are  many  excellent  types  of  spray  pumps 
on  the  market,  and  no  mistake  can  be  made  in  selecting  any  of  the 
outfits  of  the  better  manufacturers,  but  there  are  several  points  which 
should  be  insisted  upon.  The  interior  fittings  of  the  pump  should  be 
of  brass  and  should  be  arranged  so  that  the  inside  of  the  cylinder  can 
be  easily  reached  in  order  that  repairs  may  be  made.  The  air  cham- 
ber, which  insures  a  steadier  stream  and  acts  as  a  reservoir  of  force, 
is  almost  a  necessit}T.  A  pressure  gauge  upon  this  air  chamber  will 
be  of  great  value,  as  it  will  aid  the  man  who  does  the  pumping  to  keep 
the  pressure  at  about  the  same  point.  The  pump  may  be  mounted 
upon  a  barrel,  which  ma}^  be  stood  on  end  or  put  on  the  side,  or  it 
may  be  mounted  on  a  tank  or  upon  the  wagon  frame  on  which  the 
tank  is  mounted.  These  tanks  are  preferably  of  wood,  and  should  be 
of  very  strong  construction  and  securely  bolted  together  with  iron 
rods.     Screens  should  be  used  to  strain  out  particles  which  would  clog 


74 

the  nozzles,  and  should  be  used  both  as  the  water  is  put  into  the  tank 
and  as  it  is  pumped  out.  It  is  highly  essential  that  some  mechanical 
device  he  used  to  keep  the  liquid  in  agitation  so  thai  the  coarser  par- 
ticles will  not  settle  to  the  bottom  of  the  tank  and  render  the  mixture 
of  variable  strength,  especially  if  Paris  green  is  used.  The  hose  may 
he  any  of  the  types  in  use.  and  a  hose  extension  of  some  light  tube, 
covered  preferably  with  bamboo,  should  be  used  in  order  that  the  tops 
of  the  tall  trees  may  be  easily  reached.  A  stopcock  at  the  junction  of 
the  hose  and  extension  can  be  used  to  greal  advantage. 

The  nozzles  most  used  in  spraying  orchards  are  of  two  types  — those 
which  throw  a  fan-shaped  spray,  which  are  used  for  long-range  work, 
and  those  which  throw  a  cone-shaped  spray,  which  are  used  for  close 
work.  Several  of  these  nozzles  may  be  placed  on  one  bamboo  exten- 
sion, and  thus  the  amount  of  liquid  thrown  increased.  Four  lines  of 
hose  may  run  from  one  pump,  but  it  is  found  that  so  large  a  number 
causes  confusion  and  that  more  work  can  be  done  with  two  lines  of 
hose.  The  usual  number  of  nozzles  upon  each  extension  or  line  of 
hose  is  two.  The  nozzles  can  be  set  at  an  angle  to  tin4  axis  of  exten- 
sion, and  then  by  turning  the  extension  the  stream  can  be  variably 
directed.  If  the  spraying  outfit  is. small,  consisting  of  a  barrel  with  a 
pump,  it  can  easily  be  hauled  through  the  orchard  on  a  sled:  but  if  the 
out  tit  is  larger  it  is  usually  drawn  upon  an  ordinary  wagon.  Details 
of  the  mounting  on  the  wagon  and  the  position  of  the  pump  and  tanks 
will  depend  a  great  deal  upon  the  facilities  which  the  grower  has  at 
hand.  Many  have  the  tanks  and  pumps  mounted  upon  a  frame,  which 
they  can  put  upon  the  wagons  and  remove  when  the  spraying  is  com- 
pleted. If  it  is  desired  to  spray  very  tall  trees,  it  has  been  found  that 
spraying  can  be  done  more  rapidly  and  thoroughly  if  there  are  high 
platforms  built  upon  the  wagons  upon  which  the  operators  can  stand 
(fig.  IT).  The  capacity  of  these  hand-power  spraying  outfits  depends 
upon  many  factors,  such  as  the  number  of  men  employed,  size  of 
pump,  number  of  nozzles,  capacity  of  tank,  distance  from  water  sup- 
ply, and  size  of  trees.  It  has  been  found  that  three  men,  using  a  200- 
gallon  tank  and  two  lines  of  hose,  each  fitted  with  two  nozzles,  can 
spray  about  250  average-sized  trees  per  day.  These  hand-power  spray- 
ing out  (its  can  be  purchased  and  put  in  working  order  for  from  $15  to 
S7:».  A  pump,  if  used  for  arsenicals  alone  and  given  good  care. 
should  Last  for  five  or  six  years  with  but  few  repairs.  Hut  if  the 
same  pump  is  used  for  spraying  with  the  lime,  sulphur,  and  salt  com- 
pound, and  the  compound  allowed  to  corrode  the  pump,  it  will  be 
necessary  to  purchase  a  new  pump  oftener.     (See  Pis.  XI  and  XII.) 

QASOLINB-POWSB   BPRAYING    OUTFITS. 

If  an  orchard  consists  of  more  than  a  thousand  trees,  it  will  be  found 
expedient   to  use  a  gasoline-power  spraying  outfit.     If  the  orchard 


75 

consists  of  five  to  ten  thousand  trees,  it  will  be  found  that  the  expense 
per  tree  with  this  outfit  is  only  about  half  of  what  it  would  be  with 
hand-power  sprayers. 

Many  dealers  have  placed  spraying  machines  on  the  market  in  which 
the  power  is  derived  from  gasoline  engines.  They  consist  largely  of 
engines,  pumps,  and  machinery  for  other  uses,  placed  together  for 
this  purpose.  While  a  majority  of  these  are  quite  well  adapted  to 
the  work  of  spraying,  many  improvements  are  possible  which  would 


Fig.  17  — Spra\  ng  outfit  for  treating  tall  trees  (after  Gould). 

increase  efficiency  without  increasing  cost.  There  are  many  makes  of 
gasoline  engines,  most  of  which  arc  well  adapted  to  this  work.  The 
horsepower  of  the  engines  is  usually  too  large.  An  outfit  with  which 
the  writer  is  most  familiar  is  run  by  a  H-horsepower  gasoline  engine, 
and  in  ordinary  spraying  operations  it  was  found  that  the  engine  was 
too  powerful,  as  four  out  of  nine  possible  explosions  were  all  that  was 
required  to  run  the  pumps  and  keep  the  pressure  at  100  pounds.  The 
engine  for  spraying  purposes  should  be  about  1  horsepower,  which 


76 

■» 

may  be  more  than  is  required  at  ordinary  times,  but  occasions  may 
arise  when  more  power  would  be  desired. 

There  are  many  methods  by  which  gasoline  is  \'vd  into  the  cylinders 
of  these  engines.  The  better  engines  have  a  pump  by  which  the  gas- 
oline is  forced  into  the  cylinder.  The  ignition  is  accomplished  by  one 
of  two  methods  either  by  an  ignition  burner  on  the  outside  of  the 
cylinder  which  communicates  heat  to  a  platinum  point  which  explodes 
the  gasoline  vapor,  or  by  an  electric  spark  from  an  induction  coil 
which  is  connected  with  numerous  dry  batteries.  The  cooling  tank 
used  with  these  engines  for  the  purpose  of  keeping  the  cylinder  moist 
and  cool  is  usually  from  12  to  1-t  inches  in  diameter.  This  size  is 
intended  for  stationary  engines,  where  the  water  can  not  be  renewed 
frequently.  In  spraying,  however,  the  water  can  be  renewed  every 
tew  hours  if  necessary;  and  therefore  the  tanks  can  be  built  as  small 
as  6  inches  in  diameter,  which  will  make  a  considerable  reduction  in 
the  weight  of  the  machinery. 

Purchasers  are  always  given  full  instructions  in  regard  to  the  care 
and  running  of  these  engines,  so  that  one  with  comparatively  little 
mechanical  ingenuity  has  very  little  trouble.  The  greatest  source  of 
difficult}'  is  with  the  electric  current.  The  insulations  often  become 
imperfect  or  the  sparking  points  become  dirty  and  fail  to  produce  a 
spark.  By  carefully  testing  the  current  and  keeping  these  points 
clean  practically  all  of  the  trouble  is  avoided. 

It  is  preferable  to  place  the  engine  at  the  rear  end  of  the  frame  and 
the  pump  as  near  the  engine  as  possible.  There  are  two  types  of  spray- 
ing pumps  which  may  be  used  for  this  purpose — the  triplex  pump, 
which  consists  of  three  vertical  plungers,  and  the  straight  horizontal 
double-acting  force  pump.  Either  of  these  pumps  will  be  found  to 
answer  to  the  conditions  required  for  these  outfits,  but  the  horizontal 
pump  is  more  commonly  used.  The  pumps  should  be  so  manufactured 
that  all  of  the  parts  are  accessible  and  the  brass  lining  easily  removed. 
The  working  parts  should  be  made  of  brass  or  bronze.  A  large  air 
chamber  i-  essential,  as  well  as  a  pressure  gauge.  It  is  absolutely 
necessary  that  a  relief  valve  be  attached  to  the  pump,  so  that  when 

the  stopcocks  on  the  bamboo  extension  are  closed  the  engine  will  not 
have  to  be  stopped,  but  at  a  certain  pressure  the  spraying  liquid  will 
lie  returned  to  the  tank. 

In  sections  of  the  country  when*  irrigation  is  practiced  it  has  been 
found  that  the  most  effective  method  of  tilling  the  tank  is  to  have 
another  pump  which  can  be  attached  to  the  engine,  by  which  water 
can  be  pumped  from  an  irrigating  ditch  into  the  tank.  This  pump 
should  belong  to  the  type  known  as  "  low-down  pumps."  which 
deliver  large  quantities  of  water  at  low  pressure.  The  suction  hose 
should  be  2  or  3  inches  in  diameter  and  the  end  which  is  put  into  the 
irrigating  ditch  should   be  w  '1  screened.      There  is  usually  some 


77 

method  by  which  this  pump  can  be  connected  with  the  engine.  It  is 
unnecessary  to  disconnect  the  spraying  pump  from  the  engine,  as  the 

suction  hose  of  the  spray  pump  may  be  removed  from  the  spraying 
tank.  This  filling  pump  and  connections  can  be  purchased  for  about 
$20,  and  the  time  and  labor  saved  by  its  use  will  pay  for  it  many 
times  over  during  the  season.  This  idea  of  having  a  filling  pump 
attached  to  the  spraying  machine  was  originated  and  carried  out  suc- 
cessfully by  Hon.  Edgar  Wilson,  of  Boise.  Idaho. 

As  before  stated  in  regard  to  hand-power  outfits,  it  is  found  much 
more  expedient  to  use  only  two  lines  of  hose.  The  length  of  this  hose 
will  depend  upon  the  method  used  in  spraying  the  trees.  Bamboo 
extensions  and  nozzles  are  the  same  as  those  used  in  power  outfits. 
It  is  found  that  water  from  irrigating  ditches  contains  a  considerable 
amount  of  sand.  The  effect  of  the  sand  and  the  lime  in  the  spraying 
solution  is  to  cause  the  face  of  the  nozzle  to  become  badly  worn,  ren- 
dering it  unfit  for  use  in  five  or  six  days  of  continuous  spraying. 
Letters  have  been  written  to  the  more  important  manufacturers  call- 
ing their  attention  to  the  fact  that  if  the-e  faces  were  hardened  or 
made  of  steel  the  nozzles  would  last  much  longer,  and  it  may  be  that 
these  firms  will  shortly  put  such  improved  nozzles  on  the  market. 

The  tanks  used  in  these  spraying  outfits  may  be  made  of  wood  or 
galvanized  iron.  The  latter  would  be  preferable  on  account  of  its 
lightness,  but  it  would  be  disadvantageous  because  it  would  be  some- 
what difficult  to  thoroughly  brace  it.  The  tanks  should  not  have  a 
larger  capacity  than  150  gallons  and  should  be  placed  on  the  front  end 
of  the  frame.  Screens  should  be  placed  over  the  end  of  the  hose  lead- 
ing from  the  filling  pump,  as  well  as  over  the  suction  hose  from  the 
spraying  pump. 

The  agitator  which  has  given  the  best  satisfaction  in  this  connection 
is  formed  by  two  paddles  set  at  an  angle,  mounted  on  a  vertical  shaft, 
and  run  by  power  derived  from  the  gasoline  engine  by  means  of  a  belt 
and  bevel  gearing.  This  agitator  keeps  the  spraying  solution  in  violent 
agitation  and  renders  it  uniform. 

The  whole  machine,  engine,  pumps,  and  tank  should  be  mounted 
upon  a  rigid  frame.  On  this  frame  there  should  be  a  platform  at 
either  side,  with  a  railing,  upon  which  the  operators  can  stand.  There 
should  be  supports  for  the  bamboo  extensions  placed  near  the  center 
of  the  outfit.  (PL  XI.  fig.  2.)  This  frame  can  be  mounted  upon  an 
ordinary  wagon,  but  it  is  preferable  to  use  a  low  wagon  with  steel 
wheels  and  tires  not  less  than  6  inches  in  width,  which  will  largely  pre- 
vent the  wheels  from  sinking  into  the  soft  earth.  A  team  and  two 
men  are  required  to  operate  this  outfit.  Both  of  the  men  spray:  one 
drives,  and  the  other  -tarts  and  stops  the  engine.  This  reduction  of 
labor  makes  a  material  reduction  in  the  cost  of  spraying. 

Many  tests  have  been  made  of  these  machines  working  under  actual 


78 

conditions,  and  it  is  found  that  7<><>  trees  (in  the  West,  where  they  are 
considerably  larger  than  trees  of  the  same  age  in  the  East)  can  be 
easily  sprayed  in  one  day.  Some  fruit  growers  tell  the  writer  that 
they  have  been  able,  when  they  found  it  necessary  to  work  more  rap- 
idly, bo  spray  900  trees  per  day.  By  a  series  of  observations  it  has 
been  found  that  it  takes  from  four  to  five  minutes  to  till  the  tank  by 
means  of  the  filling  pump,  and  the  same  amount  of  Liquid  can  be 
sprayed  out  in  from  thirty  to  forty  minutes,  upon  from  60  to  N"  trees, 
depending  on  their  size,  using  about  2.1  gallons  per  tree.  In  an  irri- 
gated orchard  it  is  quite  desirable  that  the  ground  he  allowed  to 
become  dry  before  the  spraying  is  begun,  and  thus  avoid  miring  the 
machine  in  the  soft  earth,  which  will  frequently  occur  in  wet  places 
in  the  orchard,  especially  when  the  tank  is  full. 

The  cosl  of  these  complete  machines  varies  with  the  cost  of  the 
engine  and  pump  and  their  fittings.  They  can  be  purchased  for  from 
about  $260  to  $500.  The  machine  with  which  the  writer  is  most 
familiar  cosl  $320,  which  included  a  $40  wagon  and  filling  pump  and 
attachments  at  $20.  With  good  care  and  proper  repairs  these  machines 
can  be  made  to  last  for  several  years.  In  a  working  day  of  ten  hours 
it  was  found  that  a  1^-horsepower  engine  consumed  about  1  gallon  of 
gasoline.  Although  tin4  initial  expense  of  this  outfit  is  greater  than 
that  of  the  hand-power  outfit,  it  will  be  found  to  be  much  cheaper  in 
the  end.  as  the  engine  can  be  made  to  more  than  pay  for  itself  by 
other  uses  when  spraying  is  not  in  progress,  such  as  running  the  cider 
press,  feed  cutter,  and  cream  separator,  sawing  wood,  turning  the 
grindstone,  and  numerous  other  tasks  about  a  farm  for  which  power 
is  desired.  The  machinery  can  also  be  removed  from  the  wagon  and 
stored  in  an  outhouse  and  the  wagon  used  for  other  purposes. 

WATER   SUPPLY. 

The  distance  of  the  water  supply  from  the  orchard  is  one  of  the 
greatest  factors  in  determining  the  rapidity  with  which  spraying  can 
be  done.  With  the  water  supply  some  distance  away  much  valuable 
time  i^  lost  in  going  to  and  fro  to  till  the  tank.  In  the  smaller 
orchards,  where  but  little  spraying  is  done,  the  usual  custom  i-  to 
drive  the  wagon  to  a  ditch,  pool,  or  well,  where  the  water  is  trans- 
ferred into  the  spraying  tank  with  buckets.  .Many  fruit  growers 
have  found  it  advantageous  to  draw  their  supply  of  water  from  an  ele- 
vated tank  into  which  water  is  pumped  by  a  windmill  or  piped  from 
some  Bpring  or  stream.  For  irrigated  orchards  the  water  is  usually 
taken  direct  from  the  irrigating  ditches,  sometimes  from  the  main 
ditch  and  sometimes  from  the  lateral  ditches  running  through  the 
orchard.  By  taking  the  water  from  these  laterals  in  the  orchard  the 
routes  of  the  spraying  apparatus  in  operation  can  be  largely  deter- 
mined, the  foreman   trvine  at  all  times  to  be  near  one  of  them  when 


79 

the  tank  becomes  empty.  By  means  of  the  filling  pump  on  the  cho- 
line power  outfits  much  valuable  time  ran  be  saved  in  the  operation 

of  filling  the  tank,  as  compared  with  the  method  of  having  an  extra 
wagon  to  haul  water  to  the  spraying  outfit,  sometimes  employed.  The 
routes  followed  by  the  spraying  machine  in  the  orchard  depend  upon 
many  factors,  such  as  source  of  water  supply,  position  of  hills  and 
ridges,  and  direction  of  wind.  Each  orchard  is  a  problem  by  itself. 
and  experience  will  show  which  routes  can  be  followed  with  the  least 
loss  of  time. 

APPLICATION    <)F    SPRAY. 

There  arc  many  methods  of  spraying  the  trees.  In  following  the 
chosen  route  through  the  orchard  some  use  four  lines  of  hose,  com- 
pletely spraying  four  rows  of  trees  at  a  time:  but  it  lias  been  found 
in  actual  practice  that  on  account  of  the  long  hose  and  the  great  dis- 
tances the  men  have  to  walk  other  methods  are  more  advantageous. 
Many  use  two  lines  of  hose,  and  men  standing  on  the  ground  go  com- 
pletely around  the  trees,  thus  spraying  two  rows  on  all  sides.  Other 
fruit  growers  drive  down  one  row  and  spray  half  of  the  tree  on  either 
side:  coming  back  on  the  other  side  of  the  row  they  spray  the  other 
side  and  one-half  of  tin1  next  row.  It  ha-  been  clearly  shown  that  this 
method  gives  the  best  results,  both  in  the  saving  of  time  and  in  com- 
pletely covering  the  trees.  When  the  trees  are  tall  it  is  quite  neces- 
sary that  the  men  ride  upon  an  elevated  platform,  and  it  has  also  been 
found  advantageous  in  using  the  gasoline-power  outfit  to  have  the 
men  ride  on  the  apparatus.  In  this  way  not  only  the  men  are  saved 
unnecessary  labor,  but  from  their  elevated  position  they  can  spray  the 
tree-  more  thoroughly.  With  the  nozzle-  set  at  an  angle  on  the  bam- 
boo extension,  part  of  the  tree  can  be  sprayed  as  it  is  being  approached. 
Then  on  stopping  at  the  tree  the  whole  side  can  be  sprayed,  and  when 
leaving  it  the  last  part  can  be  sprayed  and  spraying  be  begun  on  the 
next  tree.  It  is  almost  impossible  to  spray  while  moving  at  right 
angle-  to  a  strong  wind,  and  if  such  a  wind  is  encountered  it  will  be 
found  desirable  to  have  the  wagon  go  either  with  or  against  it  and  take 
advantage  of  it  by  allowing  it  to  blow  the  mist  through  the  tree-. 
Experience  on  the  part  of  the  operators  will  enable  them  to  devise 
method-  to  reduce  the  time  without  impairing  the  effectiveness  of  the 
spraying. 

The  ideal  to  be  attained  in  applying  spray  is  to  cover  the  tree  with 
a  thin  coating  of  the  spray  solution,  so  that  when  the  water  dries  it 
will  leave  a  coating  of  poison  on  every  portion  of  the  foliage  and  fruit. 
When  the  spray  is  applied  with  but  little  force  the  stream  does  not 
break  up  into  sufficiently  fine  globules,  and  when  they  strike  the  foli- 
age they  either  cover  only  a  -mall  portion  of  it  or  run  together  into 
large  drops  and  fall  to  the  ground,  leaving  but  little  of  the  solution  on 
the  tree,  and  that  little  very  much  scattered.     If,  however,  the  spray 


80 

1h  applied  with  great  force,  the  Btream  is  broken  up  into  a  fine  mist, 

which,  if  well  directed,  is  evenly  distributed  over  the  foliage  and  fruit, 
and  upon  drying  leaves  i  more  or  less  uniform  coat.  If  the  nozzle  is 
held  close  to  the  foliage,  the  force  causes  it  to  spread  well,  but  the 
coating  is  not  so  uniform  as  that  which  is  derived  from  the  mist.  In 
spraying  one-half  of  a  tree  the  mist  drifts  through  the  tree  from  the 
side  which  is  being  sprayed,  and  in  that  way  the  tree  is  well  covered, 
having  received  practically  two  incomplete  sprayings.  If  fruit  is 
allowed  to  grow  in  clusters  it  is  necessary  to  apply  the  spray  with 
great  force  in  order  to  secure  good  results. 

MATERIALS    FOB   SPRAYING. 
CONTACT    [NBECTI4  ' 

Contact  insecticides  are  those  which  kill  the  insects  by  touching 
them.  Kerosene  emulsion  and  solutions  of  whale-oil  soap  are  the  sub- 
stances that  have  been  most  used  for  this  purpose;  hut  on  account  of 
the  expense,  the  necessity  of  frequent  application,  and  the  fact  that 
the  insect  can  he  more  easily  and  effectively  reached  in  other  stages  ]»\ 
other  insecticides,  these  kinds  of  spraying  solutions  have  been  used 
but  little  against  the  insect. 

ARSENICAL    SPRAYS. 

The  arsenical  sprays  contain  arsenic  as  their  essential  ingredient. 
Other  chemicals  are  mixed  with  the  arsenic  for  the  purpose  of  pre- 
venting it  from  burning  the  foliage  or  are  products  incidental  to  the 
numerous  compounds  of  arsenic  which  were1  used  for  other  purposes 
than  spraying,  there  are  many  spraying  compounds  of  which  arsenic 
is  the  base  on  the  market,  but  there  are  many  others  which  the  fruit 
grower  can  make  for  himself  by  combining  the  necessary  ingredients. 

"Paris  green  is  probably  the  best  known  of  these  arsenicals.  It  has 
been  used  for  many  years  with  success,  and  is  a  definite  chemical  com- 
pound of  arsenic,  copper,  and  acetic  acid.  The  composition  is  usually 
quite  uniform,  but  many  instances  have  been  found  in  which  it  was 
adulterated  or  the  percentage  of  soluble  arsenic  was  dangerously  high. 
AiJ  indicated  by  its  name,  it  is  a  substance  green  in  color.  It  is  a 
rather  coarse  powder,  which  has  the  fault  of  settling  rapidly  in  the 
spraying  tank.  It  is  quite  necessary  to  use  linn4  with  Paris  green  in 
order  t<»  counteract  the  burning  effects  of  the  free  arsenic.  Paris 
green  is  comparatively  expensive;  in  the  Bast  it  costs  about -J"  cent- a 
pound  and  in  the  West  25  cents. 

Paris  green  may  be  prepared  for  spraying  as  follows: 

Paris  green  pound..       l 

Lime pounds..       l  to 

Wane gallons..   LOO  to  260 


Bui.  41 ,  Div.  of  Entomology.  U.  S.  Dept.  of  Agriculture. 


Plate  X. 


Fig.  1.— Band  on  which  the  Remains  of  330  Cocoons  were 
Counted. 


Fig.  2.— Pupa  in  Cocoon  on  Underside  Fig.  3.— Larva  and  Pup/e  in  Cracks 

of  a  Loose  Piece  of  Bark.  in  Bark,  from  which  Rough  Bark 

has  been  Removed. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  XI. 


Fig.  1.— Gasoline-power  Sprayer,  Showing  the  Engine  and 
Spray  Pump. 


-Same  Sprayer  as  in  Fig.  1,  but  Seen  from  the  Other  Side, 
Showing  Filling  Pump  and  Attachments. 

GASOLINE-POWER    SPRAYING    MACHINES. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agncu 


:  _-e. 


Plate  XII. 


Fig.  1.— Gasoline-power  Outfit  in  the  Orchard. 


Fig.  2.— Filling  Tank  by  Means  of  the  Filling  Pump  from  an 
Irrigation  Ditch. 


Fig.  3.— Hand-power  Spraying  Outfit,  in  which  the  Pump  is  Mounted 
Upon  a  Barrel  on  an  Ordinary  Wagon. 

SPRAYING    OUTFITS    IN     USE. 


81 

The  lime  should  be  fresh  and  slaked  in  small  quantities  as  needed. 
By  mixing  a  small  quantity  of  water  with  the  Paris  green  until  a  paste 
is  formed  it  is  much  more  easily  distributed  in  the  water.  The  lime 
ma}'  be  added  to  the  water  in  the  proper  quantity. 

A  good  average  strength  of  this  solution  is  1  pound  of  Paris  green 
to  150  gallons  of  water:  but  for  trees  with  delicate  foliage,  such  as 
peach,  it  is  advisable  to  use  a  much  weaker  solution.  Many  fruit 
growers  are  using  Paris  green  of  the  strength  of  1  pound  to  100  gal- 
lon-, with  the  addition  of  lime  upon  apple  trees,  without  burning  the 
foliage. 

Sc/u  <  />  '■•<  <jr>  <  n  i-  a  similar  preparation  to  Paris  green,  but  differs  from 
it  in  lacking  the  acetic  acid.  It  is  a  finer  powder  than  Paris  green,  is 
much  more  easily  kept  in  suspension,  and  the  cost  is  only  about  half 
that  of  Paris  green.  There  is  but  little  of  this  insecticide  manu- 
factured and  placed  upon  the  market. 

L<>n<J<n,  'purple  is  a  waste  product  in  the  manufacture  of  aniline 
dyes.  It  contains  a  number  of  substances,  of  which  the  principal  ones 
are  arsenic  and  lime.  It  is  quite  variable  in  composition,  and  is  gen- 
erally considered  as  being  not  so  effective  as  some  of  the  other  arsen- 
icals.     For  spraying  it  is  now  being  replaced  by  the  other  poisons. 

Both  Scheele's  green  and  London  purple  are  prepared  for  use  in 
spraying  similarly  to  Paris  green. 

WHITE    ARSENIC   COMPOUNDS. 

If  white  arsenic  is  used  alone  in  spraying,  it  will  seriously  injure 

the  foliage  of  the  trees  by  burning,  but  when  combined  with  other 

chemicals  which  prevent  this  burning,  it  forms  the  base  of  our  most 

effective  sprays,  any   of  which  can  be  easily  prepared  by  the  fruit 

grower. 

Af*t  trite  of  It 

White  arsenic pound. .       1 

Lime pounds. .       2 

Water gallon. .       1 

The  white  arsenic  and  the  lime  are  boiled  together  for  not  less  than 
half  an  hour  in  the  required  amount  of  water,  as  it  is  very  difficult  to 
make  the  lime  and  arsenic  combine.  After  the  combination  is  com- 
plete enough  water  is  poured  in  to  replace  that  lost  by  evaporation. 
This  solution  may  be  kept  as  stock,  and  1  pint  of  it  used  to  every 
40  or  50  gallons  of  water.  It  is  advisable  to  add  more  lime  to  this 
spraying  solution  in  order  that  all  danger  of  burning  may  be  avoided. 
Although  this  solution  is  by  far  the  cheapest  spraying  material,  there 
is  much  danger  of  poor  combination  of  the  arsenic  and  lime,  leaving 
free  arsenic,  which  will  injure  the  foliage.  In  order  that  the  lime 
may  more  thoroughly  combine  with  the  arsenic,  soda  has  been  used  to 
facilitate  the  combination. 

6514^-No.  41— 03 6 


82 

ih    nj  1 1 mi    With  SOdCL. 

White  arsenic pound. .       l 

Sal  Boda  I  crj  Btal  I pounds. .       i 

Water gallon..       1 

The  ingredients  arc  boiled  in  the  required  amount  of  water  until 
dissolved,  which  will  lake  place  in  a  comparatively  few  minutes,  after 
which  the  water  lost  by  evaporation  is  replaced.     To  every  40  or  50 

gallons  of  water  a  pint  of  this  stock  solution  and  from  2  to  4  pounds 
of  fresh  slaked  lime  are  added.  The  chemical  compound  derived  from 
the  combination  of  the  sal  soda  and  the  white  arsenic  is  arsenite  of 
soda.  In  the  presence  of  lime  this  breaks  down  and  arsenite  of  lime 
i-  formed.  It  requires  4.4  pounds  of  crystal  sal  soda  or  L. 6  pounds 
of  dry  sal  soda  to  combine  with  1  pound  of  arsenic  and  -1  pounds  of 
freshly  slaked  lime  to  combine  with  1  pound  of  arsenic  to  form  arse- 
nite of  lime.  It  is  always  desirable  to  have  an  excess  of  lime  present, 
in  order  to  prevent  all  danger  of  burning;  furthermore,  this  exec--  i- 
a  convenience  to  the  fruit  growers,  because  they  can  see  by  the  distri- 
bution and  amount  of  lime  on  the  foliage  how  well  the  spraying  has 
been  done.  This  formula,  which  is  the  Kedzie  formula,  with  a  very 
few  minor  changes,  has  been  used  in  many  different  sections  of  the 
country  with  unvarying  success.  In  all  of  the  practical  tests  under  the 
advice  of  the  writer  this  solution  is  used,  and  is  found  to  be  not  only 
as  efficient  as  other  solutions,  but  far  cheaper. 

.  l/.s,  note  of  lead. 
Arsenate  of  soda ounces. .  10 

Acetate  of  lead do L' J 

Water gallons..    L50  to  200 

The  arsenate  of  soda  and  acetate  of  lead  should  be  dissolved  sepa- 
rately and  then  poured  into  a  tank  containing  the  required  amount  of 
water.  These  chemicals  unite  readily,  forming  a  white  flocculent  pre- 
cipitate of  lead  arsenate,  which  Is  easily  kept  in  suspension,  and  can  be 
used  in  excessive  strengths  on  delicate  plants  without  the  addition  of 
lime.  When  sprayed  upon  the  foliage  it  forms  a  filmy,  adhering  coat, 
which  is  but  little  affected  by  ordinary  rains.  There  are  several  good 
preparations  of  lead  arsenate  upon  the  market.  Some  of  these  are 
prepared  in  a  wet  state,  others  in  a  dry  or  powdered  form.  The  moist 
preparations  are  much  preferable,  because  the  dry  powder  does  not 
gh  e  such  a  good  coat  of  poison  upon  the  foliage.  This  poison  has  given 
excellent  results  in  use  against  the  codling  moth,  but  on  account  of  its 
expense  it  i-  comparatively  little  usi^\. 

If  it  i-  desired  to  use  Bordeaux  mixture  with  any  of  these  solutipns 
the  arsenicals  are  added  to  the  Bordeaux  mixture  in  tin1  same  propor- 
tions as  thej  would  be  to  a  similar  quantity  of  water.  At  all  times 
the  greatest  care  should  be  taken  to  prevent  accidental  poisoning  with 


83 

these  compounds. a  The  fact  should  be  firmly  impressed  upon  all  those 
who  have  anything*  to  do  with  these  solutions  that  they  arc  of  the  most 
poisonous  nature.  All  packages,  boxes,  or  bottles  containing  the 
materials  should  be  plainly  labeled  and  kept  in  secure  places  which  can 
be  locked.  The  utensils  in  which  the  mixtures  are  prepared  should 
be  thoroughly  cleansed  or  kept  in  some  secure  place,  so  that  no  mis- 
take can  occur  in  using  them  for  other  purposes. 

COST   OF   SPRAYING. 

The  cost  of  spraying  is  so  small  when  compared  with  the  benefits  to 
be  obtained  that  Ave  can  say  it  is  the  very  best  investment  the  grower 
can  make.  As  with  other  farming  operations,  the  first  }Tear  will  be 
more  expensive  than  succeeding  years,  as  by  experience  the  fruit 
grower  will  be  able  to  reduce  expense  considerably  without  impairing 
efficiency.  It  is  a  very  difficult  task  to  estimate  the  cost  of  spraying, 
for  many  factors  enter  into  the  problem.  The  initial  cost  of  the  outfit 
varies  from  $15  to  $75  for  hand-power  outfits  and  from  $260  to  $275 
for  gasoline  outfits.  These  outfits  can  be  used  for  many  years,  and 
the  parts  of  the  gasoline  outfit  can  be  used  for  other  purposes.  The 
cost  for  spraying  material  amounts  to  little. 

The  cost  of  the  different  spraying  materials  will  vary  with  the 
different  sections  of  the  country,  according  to  the  freight  rates  and 
the  quantities  purchased  by  fruit  growers.     Where  a  large  amount  of 

«  Although  no  accidents  are  known  to  have  occurred  from  the  use  of  arsenicals  in 
spraying,  it  is  well  to  know  what  to  do  in  case  of  accidental  poisoning.  If  evil 
effects  are  noted  in  the  case  of  persons  who  constantly  handle  these  poisons,  a  physi- 
cian should  be  consulted.  If  by  any  mistake  or  carelessness  a  small  quantity  is  swal- 
lowed, an  antidote  should  be  employed  without  delay.  The  following  extract  in 
regard  to  antidotes  for  arsenic  poisoning  is  taken  from  Poisons:  Their  Effect  and 
Detection,  by  A.  W.  Blyth: 

"In  any  case  where  there  is  opportunity  for  immediate  treatment,  ferric  hydrate 
should  be  administered  as  an  antidote.  This  converts  the  soluble  arsenic  acid  into 
the  insoluble  ferric  arsenate,  the  ferric  oxid  being  reduced  to  ferrous  oxid.  It  is  neces- 
sary to  use  ferric  hydrate  recently  prepared,  for  if  dried  it  changes  into  an  oxyhydrate, 
or  even  if  kept  under  water  the  same  change  occurs,  so  that  after  four  months  the 
power  of  the  moist  mass  is  reduced  to  one-half  and  after  five  months  to  one-fourth. 
When  once  the  poison  has  been  removed  from  the  stomach  by  absorption  into  the 
tissues  the  administration  of  the  hydrate  is  absolutely  useless. 

"  Ferric  hydrate  is  prepared  by  adding  strong  ammonia  to  the  solution  or  tincture 
of  ferric  chlorid  found  in  every  chemist's  shop,  care  being  taken  to  add  no  excess  of 
caustic  ammonia." 

Lime  water  may  also  be  used  as  an  antidote,  but  it  is  not  so  effective  as  ferric 
hydrate.  It  is  understood  that  after  the  antidote  some  emetic,  such  as  mustard  or 
warm  water,  should  be  administered  immediately.  Persons  who  use  great  quan- 
tities of  arsenites  in  spraying,  and  who  are  some  distance  from  drug  stores,  are 
advised  to  keep  a  small  bottle  of  each  of  the  chemicals  named  to  use  in  making  the 
ferric  hydrate.  In  preparing  ferric  hydrate  continue  to  add  the  ammonia  until, 
after  being  well  shaken,  a  faint  odor  of  ammonia  can  be  observed. 


M 

arsenites  is  u><>i\   it    is  advised  that   they  be  purchased  In  ion-pound 
using  600  gallons  of  spraying  solution  a^  a  basis.     Taking  the 
prices  of  these  different  compounds  as  they  arc  in  the  Far  West,  the 
foil   \\  ing  estimates  arc  made: 

Pai  is  green: 

Paris  green,  I  pounds,  at  25  cents $1.00 

I  J  inc.  S  ]  m»u  l  ids 04 

T<  »t  ;i  I 1 .  04 

Scheele's  green: 

Scheele's  green,  I  pounds,  at  12}  cents 50 

Lime,  s  pounds 04 

T<  »tal 54 

Lime  arsenite: 

White  arsenic,  I }  pounds,  at  Hi  rents 15 

Lime,  ■'>  pounds 015 

Additional  lime,  12  pounds 06 

Total 225 

Lime  arsenite  with  soda: 

White  arsenic,  1}  pounds,  at  10  cents r> 

Salsoda,  6  pounds,  at  1  \  cents 09 

Additional  lime, 6  pounds 03 


Total 


Lead  arsenate: 

Arsenate  of  soda,  2\  pounds,  at  10  cents 25 

Acetate  of  lead,  <>  pom  ids.  at   12  cents 72 

T«  >tal !<7 

Prepared  lead  arsenate.  36  pounds,  at  20  cents 7.20 

From  the  foregoing  quotations,  any  fruit  grower  can  estimate  the 
expense  of  spraying  by  changing  the  prices  to  those  prevailing  in  his 
vicinity.  The  prices  of  these  chemicals,  excepting  the  lime  and  sal 
soda,  are  from  about  2  to  5  cents  per  pound  more  in  the  West  than  in 
the  East.  The  labor  of  preparing,  which  is  but  little,  is  another  factor 
which  musl  i>e  included.  In  the  preparation  of  arsenicals  for  a  home 
orchard  or  a  small  commercial  orchard  it  may  be  advisable  for  the 
fruit  grower  to  purchase  the  more  easily  prepared  compounds,  such 
as  'aris  green  or  prepared  lead  arsenate,  as  this  does  away  with  much 
trouble  and  loss  of  time  in  preparing  the  .solution. 

Labor  is  the  principal  element  of  cost  in  actual  spraying  operations. 
The  cost  of  one  spraying  for  a  thousand  s  year-old  trees  in  the  far 
West,  using  2 J  gallons  of  lime  arsenite  and  soda  compound  per  tree, 
timated  as  f<»ll<»w-: 


85 

Hand-power  outfit: 

Man  and  team  4  days,  at  $3.50 $14.  00 

Two  men  4  days,  at  $1.50  each 12.  00 

Materials 1-12 

Total 27.12 

Gasoline-power  outfit: 

Man  and  team  1 J  days,  at  $3.50 5. 25 

One  man  1£  days,  at  $1.50 2.  25 

Materials -' 1. 12 

Gasoline,  lh  gallons 55 

Total 9.17 

The  above  estimates  are  taken  from  actual  conditions  in  the  field,  and 
the  prices  of  material  and  labor  are  based  upon  current  rates  in  the 
far  West,  where  they  are  considerably  less  than  in  the  East.  It  is 
assumed  that  the  men  and  teams  were  employed  at  the  local  rates; 
but  as  men  and  teams  are  already  employed  upon  fruit  farms,  the 
actual  expense  of  these  spraying  operations  is  much  smaller.  Accord- 
ing to  these  estimates  one  spraying  would  cost  2.7  cents  per  tree  if  a 
hand -power  outfit  is  used,  or  0.9  cents  per  tree  if  a  gasoline-power 
outfit  is  used.  The  additional  cost  to  the  fruit  grower  would  be  much 
less  than  this,  and  in  some  cases  would  probably  not  amount  to  more 
than  1  cent  per  tree  with  the  hand-power  outfit,  or  one-half  cent  per 
tree  with  the  gasoline  outfit. 

TIME    AND    FREQUENCY    OF    APPLICATION    OF    SPRAT. 

The  time  of  application  of  the  spray  is  one  of  the  most  important  con- 
siderations in  the  work.  It  has  been  found  that  in  many  sections  of 
the  country  fruit  growers  have  sprayed  without  any  definite  knowledge 
as  to  when  the  spray  would  be  effective,  and  many  times  it  was  not  at 
all  so,  the  effectiveness  that  it  had  depending  more  upon  chance  than 
anything  else.  Other  growers  follow  the  empirical  rule  of  spraying 
once  every  two  weeks  after  the  blossoms  have  fallen.  If  this  rule  is 
followed  no  doubt  many  of  the  sprayings  during  the  season  have  little 
or  no  effect  upon  the  codling  moth.  It  can  be  readily  seen  that  to  be 
effective  the  poison  must  be  placed  upon  the  trees  so  that  when  the 
larva?  are  hatching  they  will  get  some  of  the  poison;  but  if  they  are 
already  inside  the  apples  or  in  their  cocoons  they  suffer  very  little  from 
the  spraying.  Hence  we  find  that  where  there  are  but  two  genera- 
tions of  the  insect  there  are  only  two  periods  in  the  season  when  a 
large  proportion  can  be  affected  by  the  poison,  and  these  are  the  proper 
times  for  spraying.  The  work  done  at  these  two  periods  may  be 
termed  the  early  and  the  late  sprayings,  the  early  spraying  being- 
directed  against  the  first  generation  of  the  codling  moth. 

Two  sprayings  at  the  early  period  are  advised,  one  a  few  days  after 
the  blossoms  have  fallen  and  before  the  calyx  closes,  and  the  other 


86 

about  t\\<>  weeks  later,  when  the  majority  of  the  larvae  are  entering 
the  fruit.  There  baa  been  much  discussion  recently  in  regard  to  dis- 
pensing with  the  spraying  immediately  after  the  blossoms  have  fallen. 
It  has  been  found  that  the  larvae  enter  the  fruit  from  one  to  two 
months  after  the  blossoms  have  fallen.  In  cases  of  bad  Infestation, 
where  preventive  measures  have  been  neglected,  or  there  is  an  abun- 
dance of  the  insect,  it  might  be  well  to  make  three  sprayings  while  the 
second  generation  is  entering  the  fruit.  This  period  varies  with  the 
locality  and  with  the  seasons  in  the  same  locality:  hut  there  are  a  few 
methods  by  which  the  time  can  l>e  approximated  with  sufficient  accu- 
racy, and  in  view  of  the  fad  that  the  time  Is  Variable  the  w  liter  does 
not  w  i-h  to  recommend  that  the  spraying  he  dispensed  with  until  each 
locality  is  studied.  Spraying  may  he  begun  immediately  after  the 
first  new  entrance  holes  of  the  second  generation  are  found,  or  about 
twenty  days  after  the  date  tin'  maximum  of  the  first-generation  larvae 
are  found  under  the  bands  ready  to  spin  their  cocoons.  The  larvae  of 
the  second  generation  in  southern  Idaho  usually  begin  to  enter  the 
fruit  the  last  week  in  July,  hut  the  majority  enter  in  August,  and 
hut  few  in  September.  The  number  of  sprayings  to  be  made  against 
this  generation  depends  entirely  upon  the  success  achieved  against  the 
first  generation.  It  has  been  found  quite  definitely  that  the  injury  due 
to  the  second  generation  is  much  greater  than  that  from  the  first  gen- 
eration; and  if  the  injury  due  to  the  first  generation  is  from  2  to  5  per 
cent  the  writer  advises  a  third  spraying  for  the  second  generation; 
hut  if  the  injury  has  been  only  1  per  cent  or  less,  two  sprayings  will 
he  found  sufficient.  The  quantity  of  lime  used  in  these  late  sprayings 
should  be  reduced  to  a  minimum,  as  lime  on  the  fruit  depreciate-  its 
market  value. 

Light  showers  wash  hut  little  of  tin1  spray  from  the  tree;  hut  if 
there  is  a  heavy  shower  or  continued  lain,  a  large  amount  will  he 
removed,  and  it  will  he  necessary  to  repeat  the  sprayings  as  soon  as 
possible.  Lead  arsenate  is  less  affected  by  rain  than  the  other  spray- 
ing compounds. 

llow    THE    eoisoN    KILLS   THE    QH9ECT8. 

Though   Paris  green  has  been  used  for  spraying  purposes  for  many 

year-  with    SUCCeSS   against    the  codling   moth,  it    is  Only  recently  that 

any  serious  effort  ha-  been  made  to  ascertain  how  the  poison  is 
obtained  i>\  the  larvae.  Slingerland  was  the  first  to  answer  this  ques- 
tion with  any  degree  of  accuracy.  According  to  him  the  spray  lodges 
in  the  saucer-like  calyx  when  the  young  fruit  is  erect  after  the  blos- 
soms have  fallen,  and  up<>n  the  segments  or  leaves  of  the  calyx  clos- 
ing the  poison  is  held  there  for  some  time.  As  about  80  per  cent  of 
the  larvffi  of  the  first  generation  enter  tin1  fruit  through  the  calyx,  it 
i-  easily  seen  how  the  majority  of  them  would  obtain  some  poison. 


87 

Calyces  were  analyzed  and  the  poison  found  in  them,  showing  that 
the  closing  of  the  lobes  incloses  some  poison  at  least  two  weeks  after 
the  spraying  has  been  done.  The  writer  is  unable  to  find  any  pub- 
lished record  of  any  larva1  having  been  found  in  a  calyx,  which  were 
killed  or  supposed  to  have  been  killed  by  the  poison.  The  evidence 
which  goes  to  show  that  they  are  killed  is  all  indirect.  In  Idaho  in 
1902  the  writer  gave  special  attention  to  this  most  difficult  point.  By 
examining  the  apples  immediately  after  the  blossom  had  fallen  it  was 
found  that  the  calyx  proper  consisted  of  two  parts:  first,  the  calyx 
tube,  which  we  may  say  i^  on  the  interior  of  the  apple,  and  then  the 
lobes  or  bases  of  the  lobes  which  support  the  stamens.  The  stamens 
stand  close  together  and  form  a  sort  of  roof  over  the  calyx  tube. 
The  writer  has  many  times  (ait  open  this  calyx  tube  after  spraying- 
has  been  done,  and  was  unable  at  any  time  to  distinguish  any  particles 
of  spray  inside  the  tube.  The  writer  is  also  unable  to  give  any 
definite  figures  as  to  what  percentage  of  the  larva  enter  the  apple  by 
way  of  the  calyx  tube,  but  it  is  possible  that  it  is  large.  The  differ- 
ence in  percentages  of  larvae  which  have  entered  the  calyx  on  sprayed 
or  unsprayed  trees  should  indicate  the  efficiency  of  the  spray.  Table 
III  gives  82  per  cent  as  entering  the  calyx  on  sprayed  trees  and  80  per 
cent  on  unsprayed  trees.  There  was  lack  of  data  in  regard  to  the 
sprayed  trees,  which  was  not  discovered  until  it  was  too  late  to  obtain 
a  new  series.  Cordley  rinds  that  the  larva  do  not  enter  the  fruit 
until  two  months  after  the  petals  have  fallen,  and  on  that  account 
does  not  recommend  the  spraying  immediately  after  the  blossoms 
have  fallen. 

How  the  larva  of  the  second  generation  are  killed  is  a  question  still 
in  a  somewhat  chaotic  state.  It  is  generally  believed  that  the  larva 
get  the  poison  when  they  enter  the  fruit,  but  the  observations  of  many 
investigators,  including  the  writer,  show  that  when  the  larva1  are 
entering  they  eat  little  or  none  of  the  fruit.  In  both  sprayed  and 
unsprayed  orchards  it  is  quite  common  to  find  places  where  they  have 
entered  the  fruit  and  have  died  shortly  after  entering.  Countings  on 
4:26  new  entrance  holes  in  sprayed  trees  showed  that  there  was  an 
average  of  40  per  cent  of  the  holes  in  which  the  larva  had  died,  and 
in  two  counts  this  percentage  went  as  high  as  7<>.  Other  countings 
on  unsprayed  trees  gave,  out  of  (MM)  new  entrances.  11  per  cent  in 
which  the  larva  had  died.  As  there  is  no  way  of  knowing  accurately 
how  many  of  these  holes  were  caused  by  larvae  which  entered  the 
fruits  where  two  apples  touched,  these  data  can  not  be  relied  upon, 
but  the  writer  believes  that  during  the  period  in  which  the  entrance 
holes  were  made  at  least  10  or  15  per  cent  of  the  larvae  succumbed  to 
the  spray.  Twice  larva  were  found  dead  before  they  had  entered  the 
fruit.     "Many  times  early  in  the  season  holes  were  found,  the  making 


of  which  would  employ  the  larvae  for  several  days.     In  these  cases  it 
is  questionable  whether  or  not  the  spray  killed  the  insects. 

In  regard  to  the  entrance  of  the  second  generation,  the  Larvae  may 
get  some  of  the  poison  when  their  jaws  are  slipping  on  the  fruit  in  the 
attempt  to  make  an  entrance,  hut  at  best  the  percentage  probably 
killed  in  entering  the  fruit  can  in  no  way  account  for  the  general  effi- 
ciency of  spraying.  Considering  the  egg-laying  habits  and  the  leaf- 
feeding  habits  of  the  larvae  of  both  generations,  the  writer  is  strongly 
of  the  opinion  that  by  far  the  larger  number  of  the  larvae  killed  by 
spray  are  killed  through  eating  or  nibbling  the  poisoned  leaves  before 
they  find  fruits.  Ii  is  to  l>e  hoped  that  future  years  will  develop  more 
definite  data  on  this  subject. 

THE  BANDING  SYSTEM. 

A-  before  Indicated,  upon  leaving  the  fruit  the  larva  seeks  some 
place  in  the  crevices  or  loose  bark  in  which  to  spin  its  cocoon.  This 
fact  was  known  as  early  as  174»*>.  hut  ii  was  not  until  L840  that  Bur- 
relle,  of  Massachusetts,  discovered  that  by  winding  something  around 
the  tree  or  placing  (doth  in  a  crotch  many  larva1  would  he  induced  to 
collect  there  and  could  then  be  destroyed.  lie  recommended  destroy- 
in'  them  in  a  hot  oven.  The  banding  system  was  further  studied  and 
elaborated  by  Dr.  Trimble,  who  recommended  hay  ropes  for  hands. 
Very  soon  this  became  the  most  successful  method  used,  and  up  to 
about  L880,  by  its  use  many  fruit  growers  were  able  to  save  consider- 
ably more  of  their  fruit  than  before.  Many  other  observers  have 
made  studies  of  these  hands  and  proved  what  was  best  in  the  way  of 
material  and  the  manner  and  time  of  application,  until  now  it  is  one 
of  the  very  best  adjunct  methods  in  the  control  of  the  codling  moth. 
Generally  speaking,  the  system  of  banding  is  simply  furnishing  the 
larva  a  good  place  in  which  to  spin  its  cocoon  and  killing  it  after  it 
ha-  done  SO.      (See  PL   X.) 

The  materials  used  for  these  bands  may  be  designated  as  temporary 
and  permanent.  The  temporary  hand-  are  composed  of  hay.  paper, 
or  any  other  cheap  material,  and.  after  the  Larva?  have  entered  the 
hands,  are  burned  with  the  contained  larvae.  Permanent  hand-  are 
usually  of  doth:  these,  after  the  larvae  are  killed,  are  replaced  on  the 
tree.  The  materials  for  these  hand-  are  various,  and  it  has  been  found 
that  the  most  efficient  is  some  dark,  heavy  material.  Bands  of  thin 
muslin  are  quite  inefficient.  Professor  Aldrich  recommends  In-own 
canton  flannel.  In  orchard  practice  it  is  found  that  fruit  growers  use 
almost  any  material,  such  as  old  clothes,  burlap,  and  canvas. 

(  me  of  the  most  essential  feature-  o\'  the  banding  system  i-  to  render 
all  other  place-  on  the  tree  unsuitable  \'^v  the  spinning  of  the  cocoon. 
thus  ha\  in-.--  the  band  the  only  alternative.  Cracks  in  the  tree  should 
he  filled,  the  rough  hark  scraped  awa\ .  and  all  other  obstacles  removed. 


89 


The  band  should  consist  of  a  piece  of  cloth  long  enough  to  go  around 
the  tree  more  than  once,  and  from  10  to  1-L  inches  in  width.  This 
piece  of  cloth  is  folded  once  lengthwise  and  placed  around  the  tree. 
There  are  many  devices  for  holding  the  bands)  in  place  upon  the  tree. 
The  one  which  gives  the  most  satisfaction,  and  allows  the  hand  to  be 
removed  and  replaced  most  readily,  consists  of  driving  a  -mall  nail 
through  the  ends  of  the  band  after  wrapping  it  around  the  tree,  and 
then  nipping  off  the  head  of  the  nail  in  such  a  manner  as  to  leave  a  sharp 
point.     Subsequent  removal  of  the  band  is  accomplished  by  -imply 


;   I 


'S\ 


Tig.  1*.— Large  apple  tree  properly  banded  for  the  codling  moth 
(original). 


— Al-ple  tree  banded, 
showing  bands  both  above 
and  below  a  hole  in  the 
trunk  (original  . 


pulling  the  ends  off  the  nail,  and  replacement  by  pushing  them  down 
again  over  it.  Ordinarily  one  band  to  the  tree  is  sufficient  in  general 
orchard  practice,  but  in  cases  where  the  trees  are  large  and  have  a 
number  of  large  branches,  it  is  advisable  to  put  one  band  around  the 
trunk  and  one  around  each  of  the  larger  limbs.  (Fig.  18.)  Where 
there  are  holes  in  the  trees  which  can  not  be  rendered  unsuitable  for 
the  spinning  of  the  cocoons,  it  is  the  best  to  put  bands  both  above 
and  below  them.     (Fig.  19.) 


90 

Manx  writers  have  experimented  upon  the  effect   of  several  bands 
ii|x»n  the  tree.     Le Baron  gives  the  following  table: 

Table  VIII.     Number  of  larva  caught  under  band*. 


Date  of  examination. 

Aug.  11. 

Sept  9. 

Sept.  28. 

Kunl-  .'ii  liml-                  

i:: 
'.'I 

31 
18 

21 

7 

I.". 
21 

I 

Middle  band* 

.... 

■V 

( )n  a  single  t  ree,  from  Jul\  4  to  July  23,  t he  same  writer  found  1 1<» 
larva-  under  the  top  band  and  L50  under  the  lower  hand. 

The  author  states  that  the  windfalls  in  every  ease  were  left  as  they 
fell.  In  the  season  of  the  year  when  a  Large  number  of  the  wormy 
apples  were  on  the  ground  the  lower  band  caught  most  of  the  larvae, 
while  during  duly,  when  the  windfalls  caused  by  the  first  generation 
had  hardly  begun  to  fall,  the  larger  number  of  larvae  were  caught  bv 
the  upper  hand. 

Professor  Aldrich  experimented  upon  one  large  tree  and  five  hands. 
The  table  made  from  these  experiments  is  here  given* 

Table  IX.  —  Professor  Aldrich' 8  r<<-<,r<l  of  bands  on  one  tree. 


July— 

August — 

September— 

October— 

Total. 

7.      l.\ 

21. 

30. 

i-.. 

12. 

lv 

t. 

in. 

17. 

2.\ 

1. 

|| 

8. 

15. 

To], 

2      27 

32 

11 

7 

- 

1 

i 

6 

2 

2.1 

\:\ 

156 

Second 

ii 

1 

9 

12 

1 

6 

IS 

3 

l 

7 

8 

I 

Third 

1 

1 

:» 

12 

ll 

6 

0 

6 

2 

3 

3 

IS 

11 

- 

Fourth 

1 

I 

ll 

11 

U 

3 

4 

2 

1 

2 

i 

7 

- 

6 

76 

Bottom 

ii 

3 

7 

L8 

17 

1 

7 

8 

1 

3 

.... 

- 

9 

7 

3 

'.'7 

Total    

4 

42 

64 

ta 

63 

2:; 

32 

12 

17 

24 

:;7 

84 

494 

Out  of  a  total  of  4!>4  larvae  about  ;)<>  per  cent  were  caught  on  the 
upper  hand,  and  the  lower  hand  caught  more  than  any  of  the  inter- 
mediate one-.  The  experiment  also  shows  that  iii  seeking  a  place  for 
their  cocoons  the  larva1  will  cross  several  bands,  and  as  there  is  no 
way  by  which  those  going  up  the  tree  and  those  going  down  can  be 
separated,  no  exact  percentages  of  such  can  be  given. 

Wickson  found  by  carefully  conducted  experiments  that  while  2,704 
apples  and    pears  were  counted    from  which  lar\;e  had   escaped,  there 
were  only  L,188  under  the  bands,  or  44  per  cent.     The  remaining 
p.rc.nt  either  found  other  places  in  which  to  spin  their  cocoons  or 
were  destroyed  by  their  enemies.     The  percentage  of  larva-  caught 

upon  a  tree  will  depend   entirely  on  the  condition  of   the  tree.      If  the 

tree  is  five  from  cracks,  holes,  and  rough  hark,  more  larvae  will  he 
caught;  while  if  there  are  other  places  in  which  they  can  spin,  fewer 
of  them  w  ill  go  under  the  hand-. 

It  ha-  been  fully  demonstrated  that  in  badly  infested  orchard- of 
the  West  only  a  comparatively  -mall  percentage  of  the  fruit  can  be 

-a\  ed  l»\    hand-  alone. 


91 

After  the  larvae  have  collected  under  the  bands  they  must  be  killed 
or  the  bands  will  become  a  positive  aid  to  the  insert.  The  usual 
method  of  examining-  the  hands  is  as  follows:  One  end  is  removed 
from  the  nail  and  rolled  hack  upon  itself  around  the  tree.  As  the 
cocoons,  larvae,  and  pupa1  are  exposed  they  are  cut  in  two  with  a 
sharp  knife  or  crushed.  Many  methods  have  been  devised  by  which 
these  hands  can  he  collected  in  wagons  and  brought  to  a  central  place, 
where  they  are  put  in  hot  water,  run  through  wringers,  or  some  other 
device  used  to  kill  the  larva1:  hut  in  view  of  the  fact  that  many  of  the 
worms  will  crawl  out  in  transit,  and  comparatively  few  of  them 
remain  attached  to  the  hands,  these  methods  must  give  way  to  the 
one  described.  Another  important  point  is  the  length  of  time  which 
should  intervene  between  the  examination  of  bands  and  the  killing  of 
the  larva1.  This  time  depends  entirely  upon  the  length  of  time  which 
it  takes  the  larva  to  emerge  as  a  moth  after  having  left  the  fruit.  In 
the  warmer  sections  of  the  West  6  or  7  days  has  been  recommended. 
By  extensive  experiments  carried  on  by  Professor  Gillette  and  the 
writer  it  was  found  that  practically  none  of  the  moths  issue  until 
after  11  days  from  the  time  they  entered  the  bands.  The  data  upon 
which  the  recommendation  of  6  or  7  days  was  based  have  in  some 
cases  been  found  to  be  quite  inaccurate.  AY  hen  the  trees  were  exam- 
ined not  all  of  the  larva1  were  killed,  and  the  second  week  afterwards 
some  of  them  were  found  to  have  emerged,  and  from  this  the  conclu- 
sion was  reached  that  some  of  them  went  through  the  cocoon  stage  in 
6  or  7  days.  The  experiments  by  the  writer  and  Professor  Gillette 
have  been  found  in  practice  to  allow  a  small  number  of  moths  to 
escape.  A  person  examining  bands  frequently  can  easily  tell  whether 
the  time  is  too  short  or  too  long.  If  the  time  is  too  long,  man}' 
empty  pupa  cases  will  be  found  projecting  from  the  band,  whereas  if 
the  time  is  too  short  most  of  the  insects  will  be  found  in  the  larval 
stage,  not  having  had  time  to  transform  to  pupae. 

EXPENSE    OF   BANDING. 

When  compared  with  the  cost  of  spraying,  banding  is  comparatively 
expensive.  One  man  can  examine  the  bands  and  kill  the  larvae  on 
about  300  trees  in  one  day.  Counting  his  wages  at  $1.50  per  day.  we 
find  that  it  costs  about  £5  a  thousand  trees  for  one  examination,  which 
is  about  half  the  cost  of  one  spraying.  The  bands  should  be  placed 
upon  the -trees  in  the  spring  at  about  the  time  the  earliest  larva  of  the 
first  generation  begin  to  leave  the  fruit.  This  time  is  usually  about 
two  weeks  after  the  first  wormy  fruits  have  been  noted,  and  in  south- 
ern Idaho  is  about  June  15.  It  is  always  well  to  apply  the  bands  a 
week  or  so  earlier  than  there  is  any  necessity  for.  The  bands  should 
be  examined  every  ten  days  and  the  larvae  which  have  collected  in 
them  killed.  This  makes  about  ten  or  eleven  examinations  of  the 
bands  in  the  course  of  the  season.     Examination  after  the  first  week 


92 

in  September  is  unnecessary  in  southern  [daho  and  practically  all  of 
the  Pacific  northwest,  as  \<ty  few  moths  emerge  after  this  time. 
After  the  f i  nit  has  been  picked  and  carried  off,  the  hands  should  be 
removed,  all  the  larva*  in  them  or  on  the  trees  killed,  and  the  hands 
stored,  because  it'  they  arc  left  in  the  orchard  they  will  soon  rot. 

wiiia    BANDS    MAY    BE    USED. 

Bands  may  be  used  to  great  advantage  in  an  orchard  bearing  its  first 
crop,  which  is  hut  Little  infested.  Many  growers  whose  orchards  are 
more  <>r  less  isolated  and  hut  little  infested  use  the  banding  system  as 
a  means  of  control.  One  of  these  is  Mr.  I.  B.  Perrine,  of  Blue  Lake. 
[daho,  who  lias  had  great  success  in  keeping  the  injury  in  the  worst 
infested  section  of  his  orchard  down  to  less  than  3  per  cent. 

The  most  important  use  of  the  hands  is  as  an  adjunct  to  spraying  in 
a  badly  infested  orchard  when  it  is  desired  to  bring  the  codling  moth 
under  control  in  that  orchard,  or  in  general  practice  when  the  trees 
are  large  and  the  spraying  can  not  he  well  done  on  account  of  either 
the  inefficiency  of  the  spraying  machine  or  the  height  of  tin4  trees. 
However,  the  writer,  by  many  extensive  experiments,  lias  clearly 
demonstrated  that  when  four  or  five  sprayings  are  made  with  the 
gasoline  power  outfit,  and  the  spraying  solution  is  thoroughly  applied 
at  the  right  time,  banding  is  unnecessary.  In  orchards  where  spray- 
ing is  the  only  remedial  measure  used  it  is  advisable  to  keep  bands  on 
four  or  live  normal  trees,  killing  the  larva1  at  stated  intervals  and 
recording  the  results,  SO  that  the  hand  record  may  act  as  an  indicator 
for  the  conditions  in  the  orchard. 

PRACTICAL  TESTS. 

The  season's  work  in  L900  may  be  summed  up  in  saying  that  the 
work  accomplished  simply  outlined  the  problem  of  the  codling  moth 
in  tin'  Pacific  northwest.  In  L901  tin4  apple  crop  was  so  unusually 
small  that  all  practical  tests  which  had  been  begun  were  abandoned, 

and  the  time  devoted  to  a   study  of   the   life    history  ^(  the  insect  and 

planning  a  campaign  for  the  following  year.  It  was  decided  to  give 
the  recommendations  of  previous  years  a  thorough  practical  test  under 
actual  field  conditions  from  the  fruit  grower's  standpoint.  Some  dif- 
ficulty was  experienced  in  obtaining  orchards  in  which  to  work. 
Keeping  in  view  the  idea  that  the  codling  moth  i-  the  greatest  injuri- 
ous factor  in  the  commercial  orchard,  a  large  amount  of  work  was 
done  in  such  orchards,  the  principal  part  in  the  orchard  of  the  Wilson 
Fruit  Company,  near  Boise,  Idaho,  through  the  kindness  of  Hon. 
Edgar  Wilson,  and  in  that  of  Mi-.  Fremont  Wood.  Mr.  McPherson's 
orchard  and  that  of  Mr.  David  Geckler  were  visited  frequently  and 
observations  made.  Their  were  many  orchard-  in  various  localities 
in  which  no  mea8ui*es  were  used  against  the  codling  moth,  and  these 
were  used  a-  checks  upon  tie-  sprayed  orchards.     In  Idaho  the  injury 


93 

by  the  codling  moth  in  1902  was  (mite  variable,  as  there  had  been  but 
a  scattering  fruit  crop  the  year  before,  and  consequently  a  lack  of 
insects  in  some  localities. 

The  orchard  of  the  Wilson  Fruit  Company,  which  is  a  type  of  the 
very  best  commercial  orchards  in  Idaho,  was  planted  in  1894  by  Hon. 
Edgar  Wilson,  and  was  sold  by  him  to  the  company  which  is  the  pres- 
ent owner  in  the  early  spring  of  1902.  Mr.  Wilson  acted  a<  manager 
for  the  orchard  company  for  the  season,  aided  by  Mr.  W.  F.  Cash. 
This  orchard  consists  of  650  Ben  Davis  tree-.  500  Jonathan.  750  Rome 
Beauty.  141  Northern  Spy.  and  800  trees  which  were  planted  as  Wolf 
River,  but  were  subsequently  budded  to  Jonathan,  and  have  not  yet 
come  to  bearing.  There  are  three  short  rows  of  Pewaukee.  and  a  few 
trees  of  other  varieties  scattered  throughout  the  orchard. 

The  house  in  which  the  apples  were  packed  and  the  culls  >tored  in 
the  fall  of  1901  is  about  200  feet  from  the  orchard  and  has  always 
been  a  source  of  infection  for  it.  (PI.  IV.  figs.  '2  and  3. )  Early  in  the 
season  of  1902  Mr.  Wilson  purchased  a  gasoline-power  spray  outfit  and 
prepared  to  give  the  orchard  a  thorough  spraying.  The  improvements 
made  by  Mr.  Wilson  and  Mr.  Cash  have  rendered  this  machine  one  of 
the  most  efficient  for  this  purpose.  A  single  spraying  was  accom- 
plished in  about  four  days,  using  lime  arsenite  with  soda  exclusively 
a-  a  spraying  solution.  About  ^.U<»<>  very  heavily  loaded  trees  were 
in  bearing.  The  conditions  of  the  previous  season  were  such  that 
there  was  an  abundant  supply  of  insects  present  in  1902,  except  in  the 
Rome  Beauty  section.  The  writer  estimated  in  1901  that  from  40  to 
60  per  cent  of  the  fruit  in  the  Jonathan  and  Ben  Davis  sections  was 
infested,  no  late  spraying  having  been  made:  and  the  small  amount  of 
fruit  in  the  Rome  Beauty  section  was  all  infested. 

No  bands  were  used,  except  upon  the  trees  left  unsprayed  and  a 
very  few  near  the  apple  house.  The  blossoms  of  the  Jonathan  and 
Ben  Davis  were  fully  open  about  May  10,  and  had  dropped  about  May 
20.  The  Rome  Beauty  blooms  through  a  longer  period  of  time,  and 
some  blossoms  were  observed  as  late  as  June  1.  Spraying  should  have 
begun  about  May  l!'.  but  on  account  of  continued  rains  it  was  delayed 
until  the  23d.  at  which  time  the  orchard  was  given  a  thorough  spray- 
ing. After  two  weeks  the  orchard  was  again  sprayed,  at  about  the 
time  the  first  Larvae  were  beginning  to  enter  the  fruit.  By  the  1st  of 
July  about  all  of  the  larva?  of  the  first  generation  had  entered  the  fruit. 
Countings  on  the  Ben  Davis  and  the  Jonathan  section  gave  an  average 
of  a  little  less  than  1  per  cent  infested,  while  tin4  Pewaukee  trees, 
which  were  unsprayed.  had  from  20  to  26  per  cent  infested.  The 
Jonathan  tree  nearest  the  apple  house  had  about  5  per  cent  wormy, 
but  this  percentage  decreased  rapidly  in  the  surrounding  trees.  Other 
orchards  in  the  same  condition  showed  from  lo  to  50  percent  wormy: 
while  orchards  in  which  no  remedial  measures  had  been  applied,  and 
in  which  no  insects  were  left  over  from  the  year  before,  showed  a  very 


94 

small  percentage  wormy.  In  the  last  week  of  July,  at  about  the  time 
the  second  generation  was  beginning  bo  cuter  the  fruit,  a  third  spray- 
ing was  made:  and  the  fourth  spraying  was  made  about  August  s.  at 
which  time  a  demonstration  was  made  to  visiting  fruit  growers. 
About  ten  days  after  the  spraying  a  dashing  rain  washed  oil  a  consid- 
erable amount  of  the  spray.  Mr.  Wilson  and  Mr.  Cash  did  not  think 
it  advisable  to  make  another  spray, in  view  of  the  fact  that  the  results 
already  secured  were  ^<>  satisfactory  that  they  thought  it  unnecessary. 
There  i--  no  doubt  in  the  mind  of  the  writer  that  if  this  spraying  had 
been  made  the  results  would   have  been  better. 

Harvesting  began  about  the  second  week  in  October,  at  which  time 
the  final  results  were  obtained.  Many  trees  were  selected  early  in  the 
season  and  the  wormy  fruit  upon  them  counted:  hut  as  the  season 
progressed  the  number  was  reduced  on  account  of  the  lack  of  time  to 
make  the  proper  countings.  The  following  table  Is  compiled  from  the 
results  upon  six  average-sized  Ben  Davis  trees  which  were  situated 
about  the  center  of  the  Hen  Davis  section.  At  all  times  the  greatest 
cart'  was  exercised  in  making  these  countings  as  accurate  as  possible, 
every  one  of  the  apples  being  counted  and  no  estimates  made. 

Table  X.  —  Infested  <<n<l  non-infested  apples  on  six  si>nt>i<<l  trees. 


Num- 
ber "i" 
trees. 

Date. 

Apples  "ii  inc. 

Fallen  apples. 

Total 
apples. 

Total 

Total 

in- 
fested. 

Free. 

Total. 

In- 
fested. 

Free. 

Total. 

Per 
cciii  in- 
fested. 

apples 

in- 
fested. 

ptT 

•  •••lit  in- 
fested. 

i 

July  i»; .... 
Aug. 22  .... 

Sept.  i 

Nov.—  .... 

Total 

July  16  .... 
Aug.22  .... 

Sept.  i 

Nov.  — 

Total 

July  L6  .... 
22  .... 

Bept.4 

Nov.—  .... 

Total 

July  16  .... 
Aug.22  .... 

Total 
July  16  .... 

■i 

L2 

168 

10 

■_".• 

330 
83 

340 
112 

2 





11 

182 

1,864      1,517 

39 

us 

452 

221 

•> 

3 

(i 

19 

L43 

21 

410 
123 

431 

His 

4.8 
26 

:::::::::::::: 

171 

1.107       1,150 

,    tit; 

533 

599 

1.777           237 

13 

:; 

"    4 
in 
11 

L67 

26 

10 

1 

37 

n; 

7 

63 
26 

B 

41 
12 





... 

192 

'.'77 

l.  Ml 

37 

60 

97 

1 ,2  1 1 

229 

11 

1 

12 

0 

4 

L29 

4 

138 

in 

L65 

11 

19 



ii  > 

l . :»:.-.»          86 

L48 

179 

1,433 

181 

10 

~~T 



22 

17 

::n 

65~ 
16 
28 
63 

87~ 
28 

25 
26 

0 

. 

i 

12 



:::::::: 

168 

1 .  228 

li»7 

1,662 

13 

19 

7 

171 

l'.i 
0 

82 
16 

111 

101 
L6 

l'.'l 

1,210 

1,884 

806 

l .  892 

269 

11 

95 

The  large  amount  of  free  fallen  apples  on  trees  No.  1  and  No.  '1  are 
due  to  the  apples  picked  otf  in  the  process  of  thinning.  The  average 
total  per  cent  infested  throughout  the  season  for  these  trees  wa>  13. 

The  greatest  difficulty  was  met  with  in  obtaining  any  reliable  esti- 
mate upon  the  general  results  from  the  orchard,  for  the  reason  that 
the  larger  percentage  of  the  seconds  and  culls  were  graded  as  such 
because  they  were  small  or  uncolored.  The  Ben  Davis  section  pro- 
duced 1,944  boxes  of  strictly  first-class  fruit,  and  the  writer  estimates 
that  this  was  only  about  one-third  of  the  total  produced.  In  one  sec- 
tion of  the  orchard  there  were  trees  in  which  the  loss  was  fully  25  per 
cent  at  harvesting  time,  but  there  were  many  others  in  which  the  loss 
was  not  over  5  per  cent.  The  writer  estimates  that  at  picking  time 
about  10  per  cent  of  the  fruit  in  this  section  of  the  orchard  was 
infested.  In  the  Jonathan  section  2,030  boxes  of  first-class  fruit  were 
packed,  and  the  culls  were  estimated  at  146  boxes.  By  numerous 
counts  it  was  found  that  only  about  half  of  these  were  infested, 
which  gives  a  total  of  73  boxes  of  infested  fruit.  As  a  general  result. 
about  3  per  cent  of  the  apples  were  found  infested,  and  the  total  per- 
centage for  this  section  of  the  orchard  was  probably  about  5.  It  was 
found  that  the  tree  nearest  to  the  packing  house  was  about  50  per  cent 
wormy,  but  the  percentage  diminished  rapidly  toward  the  center  of 
the  block.  A  few  trees  which  could  not  be  well  sprayed  on  account 
of  their  situation  with  regard  to  irrigating  ditches  were  more  wormy 
than  others.  In  the  Rome  Beauty  section,  in  which  there  was  a  small 
crop  the  year  previous,  a  total  of  3,017  boxes  of  first-class  fruit  was 
packed,  and  it  was  estimated  that  one-fourth,  or  1<>9  boxes,  of  the  culls 
and  seconds  were  infested,  or  about  3  per  cent  of  the  whole  crop. 
The  Pewaukee  apples  were  practically  1<  >< )  per  cent  infested  at  the  end 
of  the  season.  The  apples  were  counted  on  an  unsprayed  Domine  tree 
September  -I.  and  81  per  cent  were  found  infested.  From  experiences 
in  other  orchards  with  this  insect,  the  writer  believes  that,  had  it  not 
been  for  spraying,  the  fruit  in  this  orchard  would  have  averaged  from 
80  to  no  per  cent  infested.     (See  Pis.  XIII.  XIV.  XV.) 

In  Mr.  Cash's  orchard,  which  is  separated  from  the  Wilson  orchard 
only  by  a  road,  it  was  found  that  the  Jonathans  were  25  per  cent 
infested,  only  two  sprayings  having  been  made. 

The  orchard  of  Mr.  Fremont  Wood,  which  i»  a  type  of  the  best  of 
the  smaller  commercial  orchards,  was  kept  under  observation  through- 
out the  season.  This  orchard  consists  of  about  1,000  trees,  the  larger 
per  cent  of  which  are  Jonathan.  These  trees  were  set  out  about  1895. 
In  1901  the  crop  was  small  and  was  almost  totally  destroyed  by  the 
codling  moth.  In  1902  a  hand-power  spraying  outfit  was  used  (PI. 
XII.  tig.  3),  which  was  supplemented  by  banding.  The  sprayings 
were  made  about  the  same  time  as  in  the  Wilson  orchard,  except  that 
the  last  -praying  was  after  the  rain,  about  the  middle  of  August,  and 


96 

it  was  probably  more  efficient  on  that  account.  A.fter  the  first  genera- 
tion of  the  larvae  had  entered  the  fruit,  it  was  found  that  there  were 
not  over  3  t<>  :»  wormy  apples  per  tree.     Harvesting  was  begun  in 

October,  and  at  that  time  it  was  found  that  in  the  Jonathan  section, 
w  hich  consisted  of  about  '."»«» t  rees,  there  were  4,700  boxes  of  first-class 
fruit  packed.  Of  culls  and  windfalls  there  were  about  900  boxes,  of 
which,  from  numerous  counts,  it  was  estimated  that  about  one-half,  or 
:»  per  cent  of  the  entire  crop,  were  infested. 

Mi-.  McPherson's  and  Mr.  Geckler's  orchards  are  types  of  old  com- 
mercial orchards  in  which  the  trees  are  large  and  the  infestation  bad. 
It  was  only  with  difficulty  that  remedial  measures  could  he  applied 
efficiently,  as  preventive  measures  had  been  neglected.  In  both 
instances,  on  account  of  the  height  of  the  trees  and  t  heir  closeness, 
the  sprays  could  not  be  well  applied.  Mr.  Geckler  estimated  his  loss 
as  high  a-  50  per  cent,  while  Mr.  McPherson  lost  as  high  as  30  per 
cent  on  the  same  varieties.  In  both  of  these  orchards  there  is  a  con- 
stant supplv  of  insects  from  other  orchards,  and  their  control  requires 
radical  application  of  preventive  and  remedial  measures. 

Mi-.  J.  A.  Fenton  estimates  that  his  crop  was  only  about  15  per  cent 
injured  in  L902,  he  having  used  bands  and  spraying.  Mr.  I.  L.  Tiner, 
who  has  a  small  orchard  in  the  city  of  Boise,  estimated  that  he  saves 
about  80  per  cent  of  Ids  fruit  each  year.  Mr.  Gus  Goeldner,  near 
Boise,  estimates  that  he  saves  90  to  95  per  cent  of  his  fruit  each  year. 
In  many  sections  of  the  West  estimates  have  been  made  by  fruit  grow- 
ers in  which  they  say  they  save  from  85  to  98  per  cent  of  their  fruit. 
Sometimes  these  estimates  are  obtained  from  countings,  but  more 
often  they  can  not  be  relied  upon,  the  fallen  fruit  not  having  been 
taken  into  consideration. 

The  results  of  practical  tests  in  these  orchards  show  that  with 
four  or  five  thorough  sprayings,  preferably  by  a  gasoline-power  out- 
lit,  from  about  85  to  95  per  cent  of  the  fruit  can  be  saved  from 
the  codling  moth.  By  a  series  of  applications  of  these  measures  even 
this  margin  of  loss  may  be  reduced;  but  the  saving  of  90  per  cent  of 
the  fruit  under  present  conditions  may  be  considered  a  solution  of  tin1 
problem. 

RESUME  AND  CONCLUSION. 

The  codling  moth,  which  is  now  a  cosmopolitan  insect,  was  intro- 
duced into  the  Pacific  northwest  about  L880.  On  account  of  the  warm 
climate  t  wo  overlapping  generations  are  produced,  and  if  proper  meas- 
ures of  control  are  neglected  the  insect,  under  normal  conditions,  will 
infest  practically  the  entire  apple  crop  of  many  localities. 

The  preventive  measures  are  fully  as  important  in  controlling  this 
insect  a-  the  remedial  measures. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agnco  ture 


Plate  XIII. 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  XIV. 


-    o 


r  o 

-  23 

tro  < 

^<  > 


33 

S     o 
o     H 

'  =        33 


Bui.  41,  Div.  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  XV. 


Clean  and  Wormy  Apples  from  Tree  No.  6.  Wilson  Orchard. 

Showing  8  boxes  of  clean  apples  and  1  box  of  wormy  apples  from  the  tree,  and  1 
of  clean  apples  and  1  basket  of  wormy  apples  from  the  ground. 


isket 


Bui.  41,  Div.  of  Entomology   U.  S.  Dept  of  Ag-  . 


Plate  XVI. 


97 

Remedial  measures  which  are  of  value  have  been  found  to  be  spray- 
ing with  arsenitea  and  banding.  Spraying  by  the  use  of  a  gasoline- 
power  outfit  has  proved  to  be  the  most  effective,  such  spiking,  using 
lime  arsenite  wkh  soda,  having  reduced  the  injury  in  a  certain  orchard 
which  had  previously  been  from  40  to  60  per  cent  to  10  per  cent. 

By  the  use  of  proper  preventive  measures,  spraying  and  banding, 
for  a  number  of  years,  the  injury  due  to  the  codling  moth  can  be 
reduced  from  nearly  100  per  cent  to  5  or  10  per  cent  in  an  orchard  in 
an}T  locality. 

BIBLIOGRAPHY  OF  MOST  OF  THE  MORE  IMPORTANT  CONTRIBU- 
TIONS TO  THE  LITERATURE  OF  THE  CODLING  MOTH. 

The  following  bibliography  down  to  1898  is  practically  a  duplicate 
of  that  published  in  Professor  Slingerland's  Bulletin  112,  Cornell 
Agricultural  Experiment  Station,  pages  63-69: 

1635.     Goedaerdt.     Metamorphosis  Xaturalis,  Vol.  I,  p.  98,  fig.  46. 

Apparently  the  first  published  account  of  the  insect.  It  seems  to  have  escaped  notice 
until  1864,  when  Werneburg  referred  to  it  in  his  •Beitrage  zur  Schmetterlingskunde." 
Lister  added  nothing  of  importance  in  his  Latin  edition  of  Goedaerdt  published  in  1685. 

1728.     Frisch.      Beschreibung  von  Allerley  Insecten  in  Teutschland,   part  7,  pp. 
16-17,  PI.  X,  figs.  1-5. 

Grotesque  and  yet  quite  accurate  descriptions  of  moth  and  larvee:  believed  it  preferred 
to  work  in  unhealthy  or  injured  fruits.     No  definite  data  on  life  history. 

1736.     Reaumur.     Mem.   pour  servir  a  L'Histoire   des   Insects,  Vol.   II,   pp.    484, 
496-499,  pi.  38,  figs.  11,  12,  and  pi.  40,  figs.  1-10. 

Good  account  of  work  of  larva  in  fruit  and  in  making  its  oocoon.  Two  broods  indi- 
cated. 

1746.  Roesel.     Insecten-Belustigung,  Vol.    I,    part  6,  Xo.  13,   pp.   33-37,    pi.   13, 

figs.  1-5. 

In  accuracy  of  detail  and  coloring  the  hand-painted  figures  equal,  if  not  excel,  any 
colored  pictures  of  the  insect  published  since.  Good  account  of  original  observations 
upon  its  life  history;  thought  the  newly  hatched  larva  sometimes  entered  the  fruit  beneath 
the  eggshell,  and  that  the  worms  sometimes  left  one  apple  and  went  to  another  fresh 
one.    One  brood  indicated.    All  stages,  except  the  egg,  well  described. 

1747.  Wilkes.     The  English  Moths  and  Butterflies,  Book  I,  class  1,  p.  5,  no.  9, 

pi.  65  (copies  of  Roesel' s  figures). 

Probably  the  first  English  account;  brief  compilation  from  Roesel.  Gave  to  the  insect 
its  name  of  "  codling  moth,"  from  the  codling  tree,  which  is  also  figured. 

1758.     Linne.     Systema  Xatura?.     Ed.  X,  p.  538,  no.  270.     Tinea  pomonella,  "Alis 
nebulosis  postice  macula  rubra  aurea." 
Original  description  of  the  insect  when  it  received  its  first  scientific  name. 

1791.     Brahm.     Insektenkalender,  Vol.  II,  p.  465. 

Brief  account  with  many  earlier  references.  Common  and  sometimes  destructive  in 
orchards;  and  records  its  habits  in  fruit  rooms. 

1802.     De  Tigxy.     Historie  Xat.  des  Insectes,  Vol.  IX,  p.  256. 

Largely  a  compilation  from  Reaumur  and  Roesel.  Says  eggs  are  laid  on  fruit  before 
petals  fall. 

1805.     Bechstein  and  Scharfexberg.     Xatur.  der  Schiid.     Forstinsekten,  Part  III, 
pp.  753-755. 

Mostly  a  compilation  from  Roesel  and  Brahm. 

1818.     Hubner.     Verz.  Bekaunt.  Schmett,  p.  375. 
6514— No.  41—03 7 


98 

1819.     Ti  1  re.     Massachusetts  Agricultural  Repository  and  Journal,  Vol.  V,  364 

\ i ■  i .: i r. •  1 1 1 1 >  the  Hr-t  account  of  the  Insecl  In  American  literature.  Previous  American 
writers  had  credited  tin-  plnm  curculio  with  the  cause  <>f  "wormy  apple-."  Records 
some  original  breeding  experiments  by  which  he  was  led  to  conclude  that  the  cause  ol 
most  "f  the  wormy  apples  In  Massachusetts  waa  a  moth,  and  n<>t  a  beetle  <>r  curculio.  ' 

1825.  Thatcher.     American  Orchardist,  second  edition,  p.  116. 

Records  finding  the  worms  <>n  1 1 1 « -  trunks  "i"  trees,  and  therefore  advises  scraping  off  the 
rough  bark  and  washing  trunks  with  Forsyth's  composition.  Apparently  the  first  notice' 
oi  the  Insecl  In  horticultural  hooks,  and  the  firsl  one  to  make  any  recommendations  ior 
controlling  the  h 

1826.  Kiuin  and  6pen<  b.     [ntroduction  to  Entomology,  III.  p.  123. 

1829.     Trkttbchkk.     Die  Schmetterlinge  vod  Europa,  Vol.  VIII,  i>i>.  lfii-ms. 

Many  references  t>>  earlier  literature.  Descriptions.  Brief  compiled  account  of  life 
history. 

1831.     CounS.     Brit  Entom.,  VUI,  pL  362. 

1833.     "  Ki  -n<  i  b."     Entomological  Magazine,  Vol.  I,  pp.  144-146. 

a  very  good  detailed  accounl  of  the  life  habits  of  the  insect.    Eggs  laid  in  the  calyx 

CUD,     <  toe  brood.     Apparently  the  first  important  article  in  the  English  literature. 

1833.  Botjchr,     Garten-Insekten,  pp.  113-114. 

Brief  compiled  descriptions  and  account  <>f  habits.  All  that  can  he  done  to  control  it  is 
to  collect  and  feed  out  all  wormy  fruit  as  fast  as  it  falls. 

1834.  &HCPHEN8.     111.  Brit.  Ent  Haust,  IV.  p.  119. 

1837.  8CHMIDBEBGEE.      In    Hollar's    Naturg.   'lor   Bchad.     Tnserten.     (For   English 

translation  Bee  Loudon  and  Westwood's  edition  of  Kollar,  pp.  229-232,  date 
1S40). 

<. 1  general  account.    Two  broods  indicated.    (He  published  an  earlier  and  more 

complete  account  in  his  Natur.  der  Obst  Bchfid.  [nsecten,  to  which  we  have  not  had 

ace.  - 

1838.  Westwood.     Gardiner's  Magazine,  Vol.  XIV.  pp.  234-239. 

Mostly  a  K<'«>d  compilation  from  the  accounts  by  Reaumur  and  "  Rusticus."    ( toe  brood 

indicated. 

1840.     Burrrllr.     New  England  Farmer,  Vol.  XVIII,  no.  48,  June  •">.  ]>.  398.     "<>n 
the  Curculio." 

Records  breeding  the  moth.    One  brood  only.    Apparently  the  tirst  one  to  suggest  the 

famous  ■•handing"  method. 

1840.  Ratzkbueg.     Die  Forst-Insecten,  Vol.  II.  pp.  234-236,  pi.  14.  fig.  7. 

Very  good  genera]  account.  Believes  there  is  but  one  brood  in  North  Germany,  and 
doubts  Bchmidberger's  account  of  two  broods  in  South  Germany. 

1841.  Harris.     Insects  of  Massachusetts,  pp.  351-355.     (In  the  editions  oi  1852 

and  L862  ro  change  occtj 
Wry  good  general  account    Only  one  brood  indicated. 

1843.  GaYLOBD.      Trail-.  N.   V.  State  Alt.  ><>c.  p.   158. 

Hrief  accounl  \\  ith  Westwood's  figure.    Recommends  allowing  swine  to  run  in  orchard. 

Insect  then  common  in  New  England,  hut  very  rare  iii  the  Middle  State-. 

1844.  L&w.     Bchadliche  [nsecten,  pp.  239-241. 

Largely  a  compilation  from  Roeeel,  with  good  discussion  of  remedies. 

1845.  Downing.     Fruits  and  Fruit-trees,  p.  66. 

Briel  account. 

1846.  Morris,  Mi-.       "Old  Lady.")     American  Agriculturist,  VoL  V,  February, 

pp.  6 

I  account,  with  original  observations,  and  illustrated  by  what  is  probably  the  tir-t 
original  Bgure  of  the  insecl  to  appear  in  American  literature. 

1849.     ( !oi  i .      Lmerican  Fruii  Book,  p 

Brief  account.    Reports  it  numerous  In  New  England  and  along  the  seaboard,  and 
ommon  In  the  Middle  State*. 


99 

1850.     Simpson.     The  Horticulturist,  Vol.  IV.  p.  567. 

Brief  account  of  breeding  experiments.  Two  or  three  broods  indicated.  Discovered 
that  a  cloth  in  the  crotch  entic-fd  many  worms,  and  after  experiments  with  wax  recom- 
mends that  trees  be  sprayed  with  whitewash  to  rill  blossom  end  of  fruits  and  thus  prevent 
egg  laying  at  this  point. 

1855.     Nokdijugkb.     Kleinen  Feinde  der  Landwirthschaft.  pp.  339-346. 

One  of  the  best  and  most  complete  accounts  which  have  appeared  in  the  German 
literature.    Very  good  discussion  of  remedies.    Bel:  -de  brooded  in  Germany. 

1859.     Jaeger.     The  Lite  of  North  American  Insects,  pp.  179-181. 
Brief,  quaint  account. 

1861.     Goureau.     Les  inseetes  uuis.  aux  Arbres  fruitiers.  pp.  118-121. 
Very  good  general  account.    One  brood  in  France. 

1865.     Trimble.     Treatise  on  the  Insect  Enemies  of  Fruit  and  Fruit  Trees,  pp.  103- 
139.     Three  full-page  colored  plates. 

One  of  the  best  accounts  in  the  American  literatuie.  Detailed  notes  on  birds  as  enemies 
of  the  insect:  'hay  bands"  devised  and  experiments  recorded.  Bred  two  broods  at 
Newark.  N.  J. 

1867.  Boisduyal.     Essai  sur  L'Entomologie  Hortieole.  pp.  560-563. 

Fairly  good  general  account.    One  brood. 

1868.  Walsh  and  Riley.     American  Entomologist.  Vol.  I.  pp.  3-6. 

Evidence  in  favor  of  allowing  hogs  to  run  in  orchards. 

1868.  Walsh.     Report  on  Insects  of  Illinois,  pp.  27-2V*. 

Arguments  for  two  broods  in  HI:: 

1869.  Riley.     First  Missouri  Kept  on  Insects,  pp.  62-^7. 

Good  general  account.    Two  br< 

1869.  Walsh  and  Riley.     American  Entomologist,  Vol.  I.  pp.  112-114. 

Very  good  general  account,  illustrated  by  Riley's  well-known  figures.    Two  broods. 

1870.  Riley.     American  Entomologist,  Vol.  II.  pp.  321.322. 

Records  experimental  proof  of  two  broods  in  latitude  of  St.  Lotus,  and  •. 
ban"  r  trapping  the  worms. 

1871.  Taschbnbkbo.     Ent.  fur  Gartner  und  Gartenfreunde.  pp.  310-313. 

Good  general  account.  Admits  but  one  generation  in  Germany.  (The  same  account 
occurs  in  his  Prak.  Insektenkunde.  III.  pp.  228-231;  date.  1880.) 

1871.  Zeller.     Stettiner  Entomologische  Zeitung,  p.  55. 

1872.  Riley.     Fourth  Missouri  Report,  pp.  22-30. 

Good  discussion  of  bands.  \Vier*s  trap,  lights,  jarring,  and  the  enemies  of  the  ins 

1873.  Riley.     Firth  Missouri  Report,  pp.  40-52. 

Records  careful  experiments  with  different  traps  on  trunk,  and  the  discovery 
para- 

1873.     LbBabok.     Third  Report  on  Insects  of  Illinois,  pp.  167- 

One  of  the  best  accounts  in  the  American  literature:  based  largely  upon  original 
vations. 

1875.     Saunders.     Report  Ontario  Entomological  Society  for  1874,  pp.  43-50. 

Good  general  account,  largely  compiled  from  LeBaron  and  Riley "s  writings.  Two  broods 
in  Canada. 

1875.     Cook,  A.  J.     Report  Michigan  Penological  Society  for  1S74.  pp.  Io2-160. 
One  of  the  be^t  accounts  in  American  literature.  1  I  upon  original  ol 

tinns.    Records  seeing  the  eggs,  but  does  not  describe  them. 

1878.  Thomas.     Seventh  Report  State  Entomologist  of  Illinois,  p.  260. 

Two  generation.",  indicated. 

1879.  Woodward.     Rural  New-Yorker.  Feb.  8  I  Proc.  West.  N.  Y.  H<>rt.  Soc.  for 

1879,  p.  20). 

First  published  account  of  successful  use  of  poisons  Paris  green )  against  the  codling  moth. 


LOO 

1880.  Cook.     American  Entomologist,  Vol.  111.  p.  263.     Also  published  in  1881  in 

Proc.  Am.  A~.  A.I.  Bci.  for  1880,  p.  669;  and  in  Kept  Mich.  Hort.  Soc.  for 
L880,  p.  136. 

Eteoordi  !ii>'  successful  use  "i*  London  purple  to  destroy  the  insect;  iir<t  test  of  poisons 
inn <  1< -  by  entomologists, 

1881.  Si  iiv.ii>i-<  ."it!  i .     Die  schad.  und  nutzlichen  [nsecten,  pp.  121-122. 

Brief  general  account. 

1881.     Cooke,     [nsects  injurious  to  California  Fruit  and  Fruit  Trees,  pp.  L3-19. 

One  of  the  best  discussions  of  the  habits  and  methods  of  fighting  it  hi  our  literature, 
ticallj  the  same  accounl  was  published  by  the  author  in  1879,  and  again  in  1888in 
hit  in.uk  on  ••  Injurious  insects, "  pp.  102  108. 1    Three  broods  Indicated. 

1883.      BA1  NDEBS.       [n8ectS  Injurious  to  I'ruit-.   pp.    127-133. 
Verj  g 1  general  discussion. 

1883.     Chapin.     Report  Second  Annual  Convention  of  California  Fruit  Growers,  pp. 

17 

Detailed  Account  of  an  extensive  experiment  with  bands  and  gathering  Infested  fruit; 
over  15,000  moths  caught  in  a  fruit  room  in  one  Beason. 

1883.     Wai.t..\.  Miss.     Report  [owa  Horticultural  Society  for  1882,  pp.  L99^-203. 
Good  genera]  account,  witli  some  valuable  breeding  experiments. 

1883.     Codlingmoth  inCalifornia  in  L883.     Ann.  Rep.  State  Board  Hort.  Cal.,  p.  is. 
1883.     Chapin.     Progress  of  the   orchards  of  California  during  L883.     Ann.  Rep. 

Cal.  State  Board  of  Hort..  p.  L2. 
1883.     Manning,  Jacob  W.     Repelling  and  destroying  codling  moth.    Trans.  Mass. 

Hort.  So,-.,  p.  10  ft 

1883.     Godfrey,  A.  N.     The  codling  moth.     Kansas  Hort.  Rept.  for  1883.     p.  91. 
1883.     Gillet,  Felix.     The  greatesl  pest  of  California  insect  pests,  or  the  codling 
moth.     In  First  Ann.  Rep.  State  Board  Hort.  Cal.,  p.  72. 

1883.  Dec     Snow.  F.  II.     The  codling  moth  or  apple  worm.     In  Quart.  Rep.  Kan. 

state  Board  Agr. 

1884.  Atkins.     Report  Maine  Board  of  Agriculture  for  L883,  pp.  356-363. 

<  toe  of  the  most  Important  contributions  t<>  the  American  literature:  it  is  based  entirely 
upon  original  observations.    One  full  brood  and  a  partial  second  one  indicated. 

1884.  LiNTNEB,  J.  A.     Apple  Worm.    Country  Gentleman  for  Oct  30,  vol.  49,  p. 

897. 
Letter  from  n.  C.  S.,  Crozet,  Va.,  In  reference  to  enemies  of  the  worm. 

1885.  Gibasd.     Traits  d'Entomologie,  Vol.  [II,  pp.  714-716. 

Good  general  account.    I  >ne  brood. 

1885.  Codlin  moth  (in  Victoria,  Australia).     Report  of  the  Secretary  for  Agricul- 

ture. 

1886.  Cbawpobd.      Report  on  Insert  Pests  in  South  Australia,  pp.  32-39. 

•  k>od  general  account. 

1886.     Whitehead.     Report  on  trisects,  prepared  for  Agricultural   Department  of 
<  rreal  Britain,  pp.  62-67. 

G l  gem  ral  account. 

1886.     Forbes.     Transactions  Illinois  Department  <d  Agriculture  for  L885,  Appendix, 
PP.  21 

Records  one  of  the  flrsl  and  most  carefully  and  Bcientiflcally  conducted  experiments 
w  1th  poison  and  lime  against  the  Insect.    Eighl  applications  made 

1886.  Gtoff.     Fourth  Report  of  New  York  Agricultural  Experiment  station. 

PP.  246  248. 

•  d-  one  of  the  flrsl  carefully  conducted  experiments  with  Paris  green, 

1887.  \\'i<  ebon.     Bulletin  75,  California  Agricultural  Experiment  station. 

Careful  comparative  experiments  with  bands  and  spraying. 
1887.     kiii~.    Sixth  \nnual  Fruit  Growers1  Convention  (of  California),  p.  -06. 


101 

1887.     Cook,  A.  J.     London  purple  against  codling  moth.     Agricult.  Sc,  T.  9,  Sept., 
1887,  p.  215. 

1887.  Forbes.     Bui.  Xo.  1,  Office  of  State  Entomologist  of  Illinois,  26  pp. 

Results  of  scientific  experiments  with  Paris  green,  London  purple,  and  arsenic  in  1886. 
Comparison  of  one,  two,  and  three  applications.    Three  broods  indicated. 

1887-88.     Claypole,  E.  W.     Spraying  for  the  codling  moth.     21st  Report  Hort.  Soc. 
Ohio,  pp.  212-214. 

1888.  Howard.     Report  U.  S.  Department  of  Agriculture  for  1887,  pp.  88-115. 

The  best  and  most  exhaustive  discussion  of  the  insect  at  that  time.     From  it  have 
been  compiled  most  subsequent  discussions  of  habits  and  life  history.    Colored  plate. 

1888.     Cook.     Bui.  39,  Michigan  Experiment  Station,  pp.  1-4. 

Results  from  one.  two,  and  three  sprayings,  and  general  conclusions  from  eight  years' 
experimenting  with  poisons. 

1888.     McMillan.     Bui.  2,  Nebraska  Experiment  Station,  pp.  68-77. 
Very  good  general  discussion  of  habits  and  especially  of  remedies. 

1888.  Popenoe   and    Marlatt.      First   Report   Kansas   Experiment    Station,    pp. 

165-193. 

Valuable  record  of  careful  experiments  with  poisons  and  bands,  including  tables  giving 
dates  of  blossoming  of  many  varieties  of  apples. 

1889.  Pissot.     Le  Naiuraliste,  p.  60. 

Notes  on  metamorphosis,  with  detailed  account  of  cocoon.    Two  broods  indicated. 

1889.     Gillette.     Codling-moth  experiments.     Bui.   7,  Iowa  Agricultural  Experi- 
ment Station,  pp.  270. 

1889.     Tryon.     Report  on  Insects  and  Fungous  Pests  (Queensland,  Australia),  No.  1, 
pp.  43-49. 

Very  good  general  account. 

1889.  Gillette.     Bui.  7,  Iowa  Experiment  Station,  pp.  270-280. 

Very  important  and  careful  experiments  with  poisons  and  carbolic  acid.     Two  broods. 

1890.  Koebele.     Bui.  22,  Division  of  Entomology,  i  .  S.  Department  of  Agriculture, 

pp.  89-93. 

New  and  important  observations  upon  the  habits  of  the  moth,  the  eggs,  and  the  enemies 
of  the  different  stages  of  the  insect. 

1890.     Olliff.     Agricultural  Gazette  of  New  South  Wales,  Vol.  I.  pp.  3-10. 
Very  good  general  account. 

1890.     Ormerod.     Manual  of  Injurious  Insects,  pp.  286-290. 
Brief  general  account. 

1890.     Cook.     Report  Michigan  Board  of  Agriculture  for  1889,  p.  320. 

Experiments  to  show  that  grass  under  sprayed  trees  may  be  safely  fed  to  stock. 

1890.  Bos.     Tierische  Schadlinge  und  Xiizlinge,  pp.  526-527. 

Brief  account. 

1891.  French.     Handbook  of  Destructive  Insects  of  Victoria,  part  1,  pp.  45-55. 

Excellent  general  account;  colored  plate. 

1891.     Beck  with.     London  purple  v.   Paris  green  for  the  codling  moth.     Bui.  12, 

Del.  Agr.  Expt.  Sta.,  p.  16. 
1891.     Hudson,  G.  V.     A  few  words  on  the  codlin  moths  (Carpocapsa  pomonella  L., 

and  Cacoeria  excessana  Walk. ).     Proc.  New  Zealand  Instit.,  vol.  23,  pp.  56  ff. 
Cacoecia  excessana,  native  to  New  Zealand,  attacks  apples  in  a  similar  way  to  Carpocapsa 

pomonella. 
1891.     Gillette,  C.  P.     The  codling  moth.     Bui.  15,  Colorado  Agr.  Expt.  Sta.,  April. 
1891.     Olliff,  A.  Sidney.     Codling  moth.     In  Agric.  Gazette,  New  South  Wales,  II, 

no.  7,  July,  pp.  385-386. 

1891.     Beckwith.     Bui.  12,  Delaware  Experiment  Station,  pp.  16-23. 

Comparative  test  of  Paris  green  and  London  purple,  showing  slight  advantage  for  the 
former. 


102 

1891.     Washbubn.     BuL    10,  Oregon  Experiment  Station,  pp.  1-lfi. 
Valuable  record  of  careful  experiments  \\  ith  i >< >i-~< •] j-  an<l  bands. 

1891.  <.iiiiiii.     r.nl.  L5,  Colorado  Experiment  Station,  pp.  4-18. 

i  in.-  of  ill"  best  aii.l  most  accurate  general  discussions  of  habits  and  remedies. 

1892.  rHoxFBON.     Handbook  to  the  [nseci  Pests  of  Farm  and  Orchard  (Tasmania), 

Part  I.  pp.  34  54. 

Ilenl  genera]  account;  two  brood* 

1892.     Lodbman.     Bul.  48,  Cornell  Experiment  Station,  pp.  i''.^-l,74. 

.!  experiments  with  combination  <'i'  poisons  and  Bordeaux  mixture. 

1892.    < » i  ii  »i.     Entomological  Bul.  I,  Dept.  Agr.,  New  South  Wales. 

1892.     Mi  toon.     Rept  Maine  Experimenl  Station  for  L891,  pp.  99  1"'.<. 
Careful  experiments  with  ixu-on^  and  Importanl  deductions  therefrom. 

1892.     Ki:i.i."....    ('..nun. >m  Injurious  [nsectsof  Kansas,  pp.  7^  - 
ount 

1892.  Townbbnd,   ( '.    II.    Tyi.ki:.     Codling  moth.     BuL  5,    New   Mexico  Station, 

March,  18 

1893.  Washburn.     Bul.  25,  Oregon  Experiment  Station,  pp.  1-8. 

Record  of  original  observations  which  form  one  of  the  most  important  and  accurate 
contributions  to  the  literature  of  the  habits  of  this  insect  yet  made.  The  egg  figured  fox 
the  first  time. 

1893.    Coquillbtt.     Bul.    o<».    Division   of    Entomology  of   U.   S.    Department   of 
Agriculture,  pp.  30-33. 

-  <>n  life  history,  supposed  enemies,  and  methods  of  combating  tin-  insect  in 
California. 

1893.     Lintnbb.     Ninth  Report  on  Insects  of  New  York,  pp.  338-342. 

Detailed  account  <>i"  the  work  of  the  Becond  brood  of  larva-  in  New  York:  and  a  discussion 
..f  the  prevalent  ideas  regarding  the  egg-laying  habits  of  the  insect 

1893.     Kii.ky.     Bul.  23,  Maryland  Experiment  station,  pp.  71-77. 

Very  g 1  general  account  of  habits,  remedies,  and  especially  oftts  enemi 

1893.  Lodkman      Bul.  60,  Cornell  Experiment  Station,  pp.  266,  273-275. 

i.xp.  riments  t«.  Bhow  that  usually  two  applications  <>i"  poisons  arc  all  that  arc  nei 
<.r  profitable  in  New  York. 

1894.  smith.     Entomological  News,  Vol.  V.  pp.  284-286. 

Records  breeding  experiments  which  indicate  hut  one  brood  of  the  insect  a;  New 

Brunswick.  N.  .1. 

1894.     Mablatt.     [nseci  Life  Vol.  VII.  pp.  248-251. 

Evidence  from  various  sources  to  show  that  insect  is  usually  double  brooded, 

1894.      SbMPBBS.      Injurious  Insect-,  pp.  ~>7-">l.». 
Brief  general  Recount. 

1894.     Schilling.     Der  Praktische  Ratgeber,  vol.  9,  pp.  1l,1-1l,:;;  133-135;  141-14::5. 
The  best  discussion  of  the  insect  from  a  practical  and  economical  standpoint  in  the 
German  literature,    <  >ne  brood. 

1894.  Iv.     Experiments  \<<v  catching  larvae  of  Carpocapm  i»>iit<>mll<i  with 

paper  rings.     Berichl  '1.   Kgl.  Lehr.  fur  Obst  Wein,  und  Gartenbau,  pp. 
21. 

1894.  I    l>.    \.     The  codling  moth.     New  Mexico  Entomologist,  No.  1, 

Apr.  21, 

1894.     Gabman,   II.     Spraying   for  codling  moth.     Bul.  •">:;.   Ky.   A.gr.   Expt.  Sta., 
December,  18 

1894.  •      es  of  the  apple  trees  an«l  its  fruit.     Nebraska  State 

Horl  »4f  p.  215. 

1894.     Wabhburm.     Bul.  31,  (  cperiment  Station. 


103 

1895.     Maklatt.     Proceedings  Entomological  Society  of  Washington.  VoL  TIL  pp. 
22^-229. 

Suggests  that  Merri&m's  life-zones  may  explain  and  determine  the  variation  in  and 
number  of  broods  of  the  insect. 

1895.     Weed.     Insects  and  insecticides.  Second  Edition,  pp.  S8-S9. 
Brief  general  account. 

1895.     Goethe.     Bericht  d.  Kgl.  Lehr.  fur  Obst.  Wein,  and  Gartenbau,  pp.  22-25. 

Records  original  observations  .from  breeding-cage  experiment  on  the  Qgg  and  on  the 
habits  of  the  young  larvae,  with  illustrations  and  descriptions.  First  definite  account  of 
these  phases  of  the  insect  to  appear  in  any  foreign  literature. 

1895.     Adkix,  Robert.     The  Entomologist,  vol.  29,  p.  2. 
Nat-feeding  habits. 

1895.     Theobald,  F.  V.     The  Entomologist,  vol.  29.  p.  28. 

Xut-feeding  habits. 

1895.     Adkix.     South  London  Entomological  Society.     The  Entomologist,  vol.  28, 
p.  345. 
Nut-feeding  habits. 

1895.     WasrwooD.     South  London  Entomological  Society.     The  Entomologist,  vol. 
28,  p.  345. 

1895.  Garman,  H.     Experiments  for  checking  apple  rot  and  codling  moth.     Bull. 

59.  Ky.  Agr.  Expt.  Sta.,  December,  1895. 

1896.  Smith.     Economic  Entomology,  pp.  322-323. 

Good  general  account. 

1896.     Lodemax.     The  Spraying  of  Plants,  pp.  252-255. 
Good  general  account. 

1896.     Slixgerlaxd.     Michigan  Fruit  Grower,  Vol.  V,  p.  8. 

Paper  read  before  Mich.  State  Hort.  Boc.  Detailed  account  of  original  observations  on 
oviposition  and  the  habits  of  the  young  larvae,  resulting  in  the  discovery  of  some  new  and 
important  economic  facts.  (The  paper  also  appears  in  Rept.  Mich.  Hort.  Soc.  for  1896, 
and  that  portion  oi  it  relating  to  the  codling  moth  in  the  Rural  New  Yorker  for  Jan.  30, 
1897.  p.  67;  and  in  the  Proc.  West.  X.  Y.  Hort.  Soc.  for  1887,  pp.  28-30. 

1896.     Bos.     Tijdschrift  over  Plantenziekten.  Vol.  XII,  pp.  52-74. 

Very  good  account  compiled  from  the  writings  of  Schilling  and  Goethe. 

1896.  Lolxsbury.     Report  Government  Entomologist  for  Cape  of  Good  Hope,  for 

1895,  pp.  33-36. 
Brief  account. 

1897.  \Valsixgham.     Proceedings  Zoological  Society.  London,  p.  130. 

Concludes  that  Cydia  iH  the  proper  generic  name. 

1897.     Smith.     Garden  and  Forest,  Vol.  X,  p.  334. 

Notes  peculiar  differences  in  habits  of  the  insect  in  Xew  Jersey,  and  especially  at  New 
Brunswick.  N.  J. 

1897.     Schoyex.     Notes  on  insects  of  Norway  and  Sweden.     Bui.  9,  n.  s.,  Div.  Ent., 
U.  S.  Dept.  ot  Agr.,  p.  80. 

1897.     Slixgerlaxd,    M.    V.     New   facts  about   the   codling   moth.     Garden   and 
Forest.  X.  468,  Feb.  10,  pp.  58-59. 

1897.     Card,  F.  W.     Notes  on  the  codling  moth.     Garden  and  Forest.  Aug.  4,  Vol. 
X.  no.  493. 

1897.     Card.     Garden  and  Forest,  Vol.  X,  pp.  302-303. 

Detailed  account  of  original  Observations  on  egg  laying  and  the  habits  of  the  young  lar- 
vae in  Nebraska.    Eggs  laid  mostly  on  the  leaves,  and  two  broods,  at  least,  indicated. 

1897.     Del  Guercto.     Bulletino  della  Soc.  Ent.  Italiana.  pp.  12-17. 
Very  good  general  account. 


104 

1897.  Card.     Bui.  51.     Nebraska  Experiment  Station,  39  p. 

Inter  it  tons  on  the  eggs  and  habits  of  the  young  larvae,  with  record 

pertinents  against  nil  stages  of  the  Insect. 

1898.  Slingebi  wi».     Tlir  codling  moth.     Bui.  Ml'.  Cornell  Univ.  Agr.  Expt  Sta., 

pp.     •_'<»  flg 
The  best  account  of  this  insect   published.    Gives  summary  of  knowledge  t<>  <lut<-. 
Including  the  greater  part  of  the  annotations  of  tin-  above  bibliography;  illustrated  with 
photographs. 

1898.     VIerriam.     Life  Zones  in  the  U.  8,     Bui.  10,  Div.  of  Biological  Survey,  U.  8. 
Dept  of  Agr. 
Describes  1 1 1 » ■  different  zones. 

1898.  Lugger,     Fourth  Annual  Report  Minnesota  Experiment  Station,  pp.  242-248. 

1899.  1I\k\i:\    vV    MlTNSON.      Apple   insects  of   Maine.      Bui.  56,  .Maine    Agr.   Expt 

Sta,     p.  L33. 

1899.     Hedrick,  W.  P.     Results  of  spraying  experiments  and  a  wasp  which  destroys 
larva?.     Bui.  64,  Utah  Expt.  Sta, 

1899.  Woodworth  &  Colby.     Paris  green  for  the  codling  moth.     BuL   126,  Cal. 

Expt.  Sta. 

1900.  Gillette.     Entomological  notes   from  Colorado.     Bui.  26,  Div.  Ent.,  U.S. 

I  >ept.  of  Agr.,  p.  76. 

1900.  Aldbich.    The  codling  moth.     Bui.  21,  Idaho  Agr.  Expt.  Sta, 

1901.  Simpson.     Report  upon  an  investigation  of  the  codling  moth  in  Idaho  in  1900. 

Bui.  30,  n.  b.,  Div.  Ent,  U.  S.  Dept.  of  Agr.,  p.  57. 
1901.    Mablatt.     Important  insecticides,  directions  for  preparation  and  use.     Fann- 
ers' Bui.  L27,  r.  s.  Dept  of  Agr. 

1901.  Simpson.     <'im  state  Rural,  No.  14. 

Published  conclusion  that  there  are  tw<>  generations  at  Boise,  Idaho. 

1902.  <  ilLLETTE       Number  of  broods  of  the  codling  moth,  as  indicated  by  published 

-lata      Ent  News,  XIII.  p.  L93. 

Oneof  the  most  complete  studies  of  the  life  history  of  any  insect.    Finds  two  genera- 
tions in  Colorado. 

1902.     <  mi. i. kith.      Life   history  studies  on    the   codling  moth.      Bui.    31,  n.   s..  Div. 

Ent,  U.  s.  Dept.  of  Agr. 
1902.     Simpson.     Report  on  codling  moth.     Investigations  in  the  Northwest  during 

1901.     Bui.  35,  n.s.,  Div.  Ent,  I".  S.  Dept.  of  Agr.     29  pp.     5  plates. 
1902.     Garcia.     Spraying  orchards  for  the   codling  moth.     Bui.  47,   New  Mexico 

Agr.  Expt.  sta. 
1902.      PlPER.      Orchard  enemies  in  the  Pacific   northwest.      Farmers'  Bui.  L53,  I  .  B 

I  >ept  of  Agr. 
1902.     Cordley.     The  codling  moth  and  late  spraying  in  Oregon.     Bui.  69,  Oregon 

Agr.  Expt.  sta. 
Finds  two  generations  *ud  note-  Important  variations  in  life  history. 
1902.     Sanderson.     Eteporl  of  the  Entomologist,  L3th  annual  report  of  Delaware 
\-r.  Expt  Sta.,  p.  17-. 

1902.  SlingEBLAND.       Trap    lanterns   or  moth    catchers.      Bui.    202,    Cornell    Tniv. 

\ -r.   Expt  Sta. 
Results  of  extended  experiments  with  trap  lanterns. 

1903.  I  The  codling  moth.     Bui.  42,  Montana  Agr.  Expt  Sta, 

1903.    Simpson.     Observations  upon  the  life  history  of  the  codling  moth.     Bui.  40, 
n.  v.  Div,  Ent,  U,  8.  Dept  of  Agr.,  p 


105 

1903.     Washburn.    A  criticism  upon  certain  codling  moth  observations.    Ibid.,  p.  65. 

1903.     Aldrich.     The  codling  moth.     Bui.  36,  Idaho  Agr.  Expt.  Sta.     16  pp. 
Reports  a  partial  third  generation. 

1903.     Busck.     Dimorphism  in  the  codling  moth.     Proc.  Ent.  Soc.  Wash.,  Vol.  V, 
No.  3,  p.  235. 

Describes  new  variety. 
1903.     Slingerland.     American  Fruit  Culturist.     The  insects  destructive  to  fruit, 
p.  177. 
A  short  general  account. 

1903.     Ferxald,  C.  H.     Bui.  32,  U.  S.  Nat.  Mus.,  p.  471. 
List  of  N.  A.  Lepidoptera,  H.  G.  Dyar. 

1903.     Webster.     The  use  of  arsenate  of  lead  as  against  the  codling  moth.     Proc. 

24th  meeting  Soc.  for  Promotion  Agr.,  pp.  65-71. 
1903.     Sanderson.     The  codling  moth.     Bui.  59,  Del.  Agr.  Expt.  Sta. 
1903.     Simpson.     The  control  of  the  codling  moth.     Farmers'  Bui.  171,  U.  S.  Dept. 

of  Agr. 
1903.     Busck.     Journal  New  York  Entomological  Society,  Vol.  XI,  June. 

Restores  generic  name  Carpocapsa. 

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